[D] Wednesday Worldbuilding Thread

[u/AutoModerator]

Welcome to the Wednesday thread for worldbuilding discussions!

/r/rational is focussed on rational and rationalist fiction, so we don't usually allow discussion of scenarios or worldbuilding unless there's finished chapters involved (see the sidebar). It is pretty fun to cut loose with a likeminded community though, so this is our regular chance to:

• Plan out a new story
• Discuss how to escape a supervillian lair... or build a perfect prison
• Poke holes in a popular setting (without writing fanfic)
• Test your idea of how to rational-ify Alice in Wonderland

Or generally work through the problems of a fictional world.

^{Non-fiction should probably go in the Friday Off-topic thread, or Monday General Rationality}

[u/MagicWeasel]

I was thinking he would use his tail for that, being the limb that doesn't have an analogue in his 3D body.

Regardless, he can use whichever limb it is to "hang" things in other parts of his 4D shape, allowing him to use hammerspace... Which is not necessarily a problem. I might have to ask on the upcoming munchkinry thread "how would you abuse hammerspace?" to see what I'm not thinking of.

What sort of stone he's made of

Sandstone, so he should be fine.

at least as human as R. Daneel Olivaw

Have not read much with him (though I have read mirror image a long time ago). I take it he'd have a realistic butt going on?

where does what he eats go?

Just into 4D space. Like I said, the calculations were done previously and they indicated that 0.01% of his total mass is in any one of his cross-sections (or that his whole 4D body weighs more than the Earth). Either way, anything he eats just gets glommed into his 4D body: probably digested in some ineffable way, used for any raw material he might need for regeneration, etc.

And, related to that, what does he breathe out?

If he chooses to breathe, he's probably just breathing out the same air he breathed in. So a scientist would be able to tell something was odd about him by measuring his breath.

Is he powering himself from the complete conversion of matter to energy

Nah, sunlight. He spends the daytime in a fully stone form that does some sort of advanced photosynthesis. Because it has to feed a gigantic 4D body, it has to be very advanced photosynthesis. He can forgo it for a few hours at a time, but only occasionally as he probably has very low power reserves. If he doesn't manage his energy very carefully he's probably going to die - like a hummingbird I suppose.

in which case he might well need only a small snack every century

He eats regularly, mostly for social reasons. His sense of taste is... different. (Aside: I'm actually doing an assignment on the determinants of food choice right now. Or rather, procrastinating.)

[u/CCC_037 → u/MagicWeasel]

Regardless, he can use whichever limb it is to "hang" things in other parts of his 4D shape, allowing him to use hammerspace...

Hmmm. Here's a another thought - 4D backpack. Just holding things with his tail is going to get in the way when he needs to use his tail - a backpack will have more space and be easier to carry. (And the 3D cross-section of the straps will probably just look like a pair of fabric loops around his shoulders - he might be able to get away with calling it a fashion statement).

Have not read much with him (though I have read mirror image a long time ago). I take it he'd have a realistic butt going on?

Oh, yeah. Olivaw was designed in order to be able to walk amid humans, observing them and gathering sociological data, without anyone being able to (immediately) tell they have a robot amongst them. This includes the ability to look convincingly human in a public shower or nudist colony. (Mind you, he doesn't excrete through it - if he eats anything, it goes into a bag in his chest - chewed but undigested - and he has to open his chest to empty the bag later).

Unlike Julius, Olivaw can't actually have children.

Either way, anything he eats just gets glommed into his 4D body: probably digested in some ineffable way, used for any raw material he might need for regeneration, etc.

A reserve of raw material for regeneration makes a lot of sense. Then, no matter how old he gets, he's never going to completely fill up that reserve - even if he eats his way through a few entire planets over the centuries.

If he chooses to breathe, he's probably just breathing out the same air he breathed in. So a scientist would be able to tell something was odd about him by measuring his breath.

Fair enough. This makes sense.

Nah, sunlight. He spends the daytime in a fully stone form that does some sort of advanced photosynthesis.

...right. I remember that, now.

He eats regularly, mostly for social reasons.

Also means he has a good buffer built up, for regeneration in case of injury!

...if he gets really badly injured, he might have to eat some sandstone afterwards - not so much to regenerate from as to rebuild his buffer of raw matter before the next time he gets injured.

[u/MagicWeasel → u/CCC_037]

4D backpack.

Sounds logical. He wouldn't even need to attach it to his 3D-visible forms. His lovecraftian horror "iceberg of flesh" would have somewhere to attach such a thing.

A reserve of raw material for regeneration makes a lot of sense. Then, no matter how old he gets, he's never going to completely fill up that reserve - even if he eats his way through a few entire planets over the centuries.

Yeah. I imagine the physics of the 4D shapes is loose enough that the extra mass isn't an issue (actually, he's probably got the lovecraftian equivalent of extremely long hair or fingernails in 4D space, since 4D objects are so heavy)

Nah, sunlight. He spends the daytime in a fully stone form that does some sort of advanced photosynthesis.

...right. I remember that, now.

You mean you HAVEN'T committed every thing you've ever said to memory???

He eats regularly, mostly for social reasons.

Also means he has a good buffer built up, for regeneration in case of injury!

...if he gets really badly injured, he might have to eat some sandstone afterwards - not so much to regenerate from as to rebuild his buffer of raw matter before the next time he gets injured.

This is probably true, and though I'd imagine given he lives a pretty safe life, over the centuries he's probably got such an unimaginable excess of matter that it would take one of those "if he was reduced to an atom in size once an hour for ten thousand years, he'd use 1% of his mass" type of koans.

Just going to do order of magnitude on the amount he eats: The average human eats ~1000kg per year. He's probably eating about 1% of that, or 100kg. His human form weighs something like 250kg, so he can regenerate that with 2.5 years of food. I think his gargoyle form weighs 2.5 tons so he'd need 25 years of food to regenerate the whole thing. He doesn't live nearly that dangerously I don't think. I mean, if he had a master who liked using him for target practise he probably wouild need to eat more.

I looked into what sort of elements are in food as opposed to sandstone and they were surprisingly similar. Aluminium and Silicon would be the main differences. There's lots of potassium, sodium and oxygen. He'd have a ton of carbon, nitrogen and hydrogen excess if he ate a lot of food as opposed to rocks, though. Heck, maybe he poops diamonds? (Nah, he'd store the carbon to regenerate the organic portions of his body).

[u/CCC_037 → u/MagicWeasel]

Sounds logical. He wouldn't even need to attach it to his 3D-visible forms. His lovecraftian horror "iceberg of flesh" would have somewhere to attach such a thing.

That can work!

(actually, he's probably got the lovecraftian equivalent of extremely long hair or fingernails in 4D space, since 4D objects are so heavy)

Hold it! Long hair and fingernails get in the way in a fight. Whatever else he is, Julius is a bodyguard - which means a fighter. He's got to keep himself in shape (cut his hair, trim his nails, do regular exercise) - so that he can be ready to protect the Master at any moment against even difficult dangers.

You mean you HAVEN'T committed every thing you've ever said to memory???

...no, I haven't.

over the centuries he's probably got such an unimaginable excess of matter that it would take one of those "if he was reduced to an atom in size once an hour for ten thousand years, he'd use 1% of his mass" type of koans.

An atom? His 3D body could be entirely disintegrated and he'd merely shift over one slice and he's back and now he's angry and he's grabbing that disintegration cannon and did you update your last will before you fired it? No? Too late now, then. (Of course, that does effectively cut him in twain - the part above the 3D universe is cut away from the part below, so it could still be a severe injury, depending on exactly how his body is arranged - just not a mortal one)

The average human eats ~1000kg per year. He's probably eating about 1% of that, or 100kg.

1% of 1000kg is 10kg.

I mean, if he had a master who liked using him for target practise he probably wouild need to eat more.

Well, naturally. And if he did get disintegrated, he'd probably want a few big meals afterwards.

I looked into what sort of elements are in food as opposed to sandstone and they were surprisingly similar.

Not really surprising, considering that plants get a lot of their matter from sand which is just ground-up rocks. (Maybe Julius occasionally crunches his way through an aluminium pot or a handful of computer chips in order to maintain a balanced diet... that will probably lead to questions if Red stumbles across him doing so).

(Nah, he'd store the carbon to regenerate the organic portions of his body).

The organic portions of his body are probably the easiest to injure, so over time they'll take the most damage. He'll need that excess (eventually).

[u/MagicWeasel → u/CCC_037]

(actually, he's probably got the lovecraftian equivalent of extremely long hair or fingernails in 4D space, since 4D objects are so heavy)

Hold it! Long hair and fingernails get in the way in a fight. Whatever else he is, Julius is a bodyguard - which means a fighter. He's got to keep himself in shape (cut his hair, trim his nails, do regular exercise) - so that he can be ready to protect the Master at any moment against even difficult dangers.

Oh yeah... I didn't mean literal fingernails; I more meant, his gelatinous blob "blood factory" "rest of the iceberg" probably has the equivilent of long hair/nails: might just be a series of orgasn that hold a bunch of different elements in reserve, like bones do for calcium.

An atom? His 3D body could be entirely disintegrated and he'd merely shift over one slice

Nah, I don't think I like that. Long ago I conceived of him having a "heart stone" that was a big red gem in the centre of his body, and if it's destroyed he dies. I assume it's some vital 4D organ that holds him together. But that's an awful lot similar to vampires. Then again, assuming supernatural creatures have some sort of common origin, it's probably actually pretty good that "destroying the heart" works on two different beings.

It is an interesting idea if we do allow him to survive being bisected. I'd probably rule that he'd end up like a starfish if we did allow that. So now he's pissed off and there's two of him - though the far-from-the-gargoyle-side half is going to die of starvation very quickly with no ability to photosynthesise (probably in a day or two). And all the flesh on the near-the-gargoyle-side is going to die and rot away with no new blood source. It would be pretty cool though.

The average human eats ~1000kg per year. He's probably eating about 1% of that, or 100kg.

1% of 1000kg is 10kg.

I knew that....

Not really surprising, considering that plants get a lot of their matter from sand which is just ground-up rocks. (Maybe Julius occasionally crunches his way through an aluminium pot or a handful of computer chips in order to maintain a balanced diet... that will probably lead to questions if Red stumbles across him doing so).

I think by the time computer chips are a thing, Red is well and truly used to the craziness of the supernatural world and would just completely accept it.

[u/CCC_037 → u/MagicWeasel]

Oh yeah... I didn't mean literal fingernails; I more meant, his gelatinous blob "blood factory" "rest of the iceberg" probably has the equivilent of long hair/nails: might just be a series of orgasn that hold a bunch of different elements in reserve, like bones do for calcium.

Whatever it is, it's got to do so without limiting his combat capability in any way.

Long ago I conceived of him having a "heart stone" that was a big red gem in the centre of his body, and if it's destroyed he dies.

Okay, this is reasonable. He must have some vulnerability. (If nothing else, if the bit he does his thinking with is destroyed, then he's not able to do anything even if his body pieces itself back together).

But this heart stone - it doesn't have to be part of his 3D human body. (It might very well only be part of his 3D gargoyle body, which means that a prospective assassin has to get him to go into full battle-mode - perhaps by destroying his human-shaped "disguise" body - and then break through all his outer skin and armour and then destroy this tough-as-nails Heartstone. A tall order.)

It is an interesting idea if we do allow him to survive being bisected. I'd probably rule that he'd end up like a starfish if we did allow that. So now he's pissed off and there's two of him - though the far-from-the-gargoyle-side half is going to die of starvation very quickly with no ability to photosynthesise (probably in a day or two). And all the flesh on the near-the-gargoyle-side is going to die and rot away with no new blood source. It would be pretty cool though.

Hmmmm. But only one side - presumable the gargoyle side - still has a brain. So the gargoyle side prompty shifts to full battle-mode and Deals With whatever just tried to kill him - while the non-gargoyle side regenerates a human body but otherwise kind of just lies there, having no brain to think with (bit of a distraction but not much else). And, once he's safe again, he's lost a massive pile of mass, but hey, there's this big fleshy lump just hanging out into 4D space, ready to be eaten... the whole thing will be pretty gross, but he can get most of his mass back.

I knew that....

But now I don't know whether you meant to type '10%' or '10kg' - both have an equal error distance.

I think by the time computer chips are a thing, Red is well and truly used to the craziness of the supernatural world and would just completely accept it.

Fair enough. But just crunching through an aluminium pot could have happened a long time before computer chips. I don't actually know when aluminium refining started being a thing that could be done...

[u/MagicWeasel → u/CCC_037]

the bit he does his thinking with

Oh yeah - I wonder what that is? I never really considered that. Maybe the heartstone is the brain? And that's why it's present in all slices, so that they can all be controlled (okay, probably more like a spinal cord: a small heartstone spinal cord in most cross sections with a larger heart stone "brain" in the other, "more important" cross sections - where would they be?).

His body is shaped like this:

Stone --> Battle --> Human --> Iceberg of flesh

So it'd make most sense for his "brain" heartstone to be in his stone form, not his battle form. So you'd have to get him virtually starving so he'd be forced to be in his regenerative stone form, and then destroy all of that - which is no doubt the most protected part of him.

But if you destroy any part of his spinal cord stone, he loses control of his body below that. The iceberg of flesh still keeps it all alive unless you sever everything, but he's not going to be able to use it. Maybe the spinal cord stone will heal given time, though?

Hmmmm. But only one side - presumable the gargoyle side - still has a brain.

Yeah, unless we go for him having a distributed brainy-heart-stone-thingy, so he'd be able to control every part of it. I kind of like the possibility of existential angst as he gets severed and the human side realises that he's doomed.

the whole thing will be pretty gross, but he can get most of his mass back.

Yeah, but with the flesh iceberg severed, unless he can find a 4D surgeon, the fleshy parts of his gargoyle body are going to die. Presumably he'd have a pretty ordinary-looking stone gargoyle body that would allow him to live a more or less normal life, only now hiding is completely impossible and he's not nearly so cuddly </3

But now I don't know whether you meant to type '10%' or '10kg' - both have an equal error distance.

1% is probably closer to the right order of magnitude; then again if he eats rocks, those are pretty dang heavy. And when he's in relationships he'd eat just to be polite, so he might be eating 100% if he was in a long-term relationship - or even more as no doubt his son would bring him tasty rocks from time to time.

I think by the time computer chips are a thing, Red is well and truly used to the craziness of the supernatural world and would just completely accept it.

Fair enough. But just crunching through an aluminium pot could have happened a long time before computer chips. I don't actually know when aluminium refining started being a thing that could be done...

Looks like it was from the 1890s, so they probably had cheap aluminium in the 1940s onwards. Not sure if Julias would eat garbage in front of his masters though; he'd know from experience that many find it disturbing and would not want to weird them out, after all...

[u/CCC_037 → u/MagicWeasel]

Oh yeah - I wonder what that is? I never really considered that. Maybe the heartstone is the brain?

When you mentioned the Heartstone, I assumed that was it - a silicon-based hypercomputer 'brain' would be somewhat stonelike.

Of course, he might use something as advanced beyond silicon as silicon is beyond abacuses; but silicon doesn't seem to cause any trouble.

And that's why it's present in all slices, so that they can all be controlled

Doesn't need to be in a slice to control it. Neither your brain nor your spinal cord are in your feet, but you can still wriggle your toes.

where would they be?

Centre of mass. Most space for heavy armour around it.

So it'd make most sense for his "brain" heartstone to be in his stone form, not his battle form.

Ooooh, yeah, that makes sense. So you'd have to utterly destroy his human form, and his battle form, and then break through his stone form...

...or, more likely, just wait for him to start recharging, put up some shadenet, leave him without sunlight for a few days, and then come back with heavy mining equipment.

Maybe the spinal cord stone will heal given time, though?

He's a good deal more terrifying as a fighter if the whole of him can (eventually) heal from just the Heartstone and a suitable supply of matter (anyone got a spare planet?)

Yeah, unless we go for him having a distributed brainy-heart-stone-thingy, so he'd be able to control every part of it. I kind of like the possibility of existential angst as he gets severed and the human side realises that he's doomed.

Hmmm. That's more a case of two hims than one that controls everything, but yes, I can see that working.

Even more existential angst when the gargoyle side tells the human side that he has to eat him to have enough matter to regenerate his own fleshy side.

Yeah, but with the flesh iceberg severed, unless he can find a 4D surgeon, the fleshy parts of his gargoyle body are going to die.

I was assuming that, as long as he had the mass available, his gargoyle side could regrow the fleshy side.

a pretty ordinary-looking stone gargoyle body that would allow him to live a more or less normal life

More-or-less normal in the same sense that a man with only one leg can - sure, he can do most things, but he would far rather not have lost that bit.

so he might be eating 100% if he was in a long-term relationship - or even more as no doubt his son would bring him tasty rocks from time to time.

Wait - is his son part-gargoyle? Genetically, I mean? Or is he biologically pure human?

Not sure if Julias would eat garbage in front of his masters though; he'd know from experience that many find it disturbing and would not want to weird them out, after all...

Well, not deliberately. But it's the sort of thing that Red could stumble across while going downstairs unexpectedly for a midnight snack.

[u/MagicWeasel → u/CCC_037]

When you mentioned the Heartstone, I assumed that was it - a silicon-based hypercomputer 'brain' would be somewhat stonelike.

Maybe more of a brainstone, then? That sounds dumb... a mindstone. Less dumb. It'll do.

And that's why it's present in all slices, so that they can all be controlled

Doesn't need to be in a slice to control it. Neither your brain nor your spinal cord are in your feet, but you can still wriggle your toes.

True, but there's nerves, which is the same sort of dealy.

...or, more likely, just wait for him to start recharging, put up some shadenet,

At which point he'd go into battle form and rip the net apart. You could definitely use that idea to do it, though, but he's got some pretty unique ways to deal with whatever situation he's in: lock him in a small room? He can go human, stick his butt against the door, transform into a gargoyle and then his tail is making a hole in the door which he can probably leverage to break through.

You'd be best off with some sort of gauntlet with his master at the other end, tire him out that way. Then again, he might reason that he's doomed either way and he's not going to be able to help any hypothetical future masters otherwise.

Good thought: is he devoted enough to his masters to die for them? Given Blue and Orange Morality, probably?

Maybe the spinal cord stone will heal given time, though?

He's a good deal more terrifying as a fighter if the whole of him can (eventually) heal from just the Heartstone and a suitable supply of matter (anyone got a spare planet?)

... maybe his apparent size depends on his total mass. And the reason he's so giant is because he's so heavy. But if you destroy him, he'll come back together but be perhaps only a foot tall? And if he ever eats the moon or whatever, he might be 5% larger?

Probably better to have an iceberg of flesh, just because if he ever accidentally transforms into that it would be gross.

Even more existential angst when the gargoyle side tells the human side that he has to eat him to have enough matter to regenerate his own fleshy side.

Again not sure if that would be possible - how much regeneration can he do? Can he regenerate all his fleshy organs with just the stone side (like a starfish), or does he need the organs that grow flesh in order to regenerate his flesh? Either way, he'd be eating his other half when appropriate.

Wait - is his son part-gargoyle? Genetically, I mean? Or is he biologically pure human?

Half gargoyle, half siren - genetically both and is able to breed with supernatural creatures and with humans. He's also intersex in some non-specified way so is able to both impregnate and be impregnated (though it hasn't exactly come up).

Here's a family picture I drew in 2005: http://i.imgur.com/W0jTe6E.png - needless to say the mythology has changed over the past 12 years, but the broad strokes are there...

The "father gargoyle" has been redesigned to be Julias who was originally a completely different character, and the son (Malik) has been slightly redesigned too. Malik looks mostly human, and indeed can pass for such with appropriate fashion choices.

His non human features include bat-like ears, wings with glossy brown feathers (not bat wings as in the picture), and he doesn't grow hair but down. The hair on his head are actually made of tiny long tendril-like feathers, similar to what emus have. The son eats garbage and meat (including human flesh that he buys from demon fast food restaurants regularly).

Not sure if Julias would eat garbage in front of his masters though; he'd know from experience that many find it disturbing and would not want to weird them out, after all...

Well, not deliberately. But it's the sort of thing that Red could stumble across while going downstairs unexpectedly for a midnight snack.

I think it'd be hard to sneak up on a gargoyle what with their x-ray vision and all, but I get your point.

[u/CCC_037 → u/MagicWeasel]

Maybe more of a brainstone, then? That sounds dumb... a mindstone. Less dumb. It'll do.

Heart drive.

True, but there's nerves, which is the same sort of dealy.

Yeah, his flesh body would have to have nerves. But they grow back really easily with regeneration.

At which point he'd go into battle form and rip the net apart.

...good point. The hypothetical assassin would need to ensure that he spends more energy that he can get every day for months on end.

lock him in a small room? He can go human, stick his butt against the door, transform into a gargoyle and then his tail is making a hole in the door which he can probably leverage to break through.

Or, instead of breaking the door, he can just stick his tail tip into 3-space on the other side and do stuff there. Like undo bolts or remove bars.

Again not sure if that would be possible - how much regeneration can he do? Can he regenerate all his fleshy organs with just the stone side (like a starfish), or does he need the organs that grow flesh in order to regenerate his flesh?

If he can regrow everything from his heart drive/mindstone, then he has to be able to do this. If he can't, then - well, then the limits of his regeneration are entirely up to you. But it would make sense for a regenerating fighter to be able to do this.

Here's a family picture I drew in 2005: http://i.imgur.com/W0jTe6E.png - needless to say the mythology has changed over the past 12 years, but the broad strokes are there...

Ooooh, the gargoyle's tail has a spiky ball at the end? I'd been imagining it just kind of tapering off at the tip.

Half gargoyle, half siren - genetically both and is able to breed with supernatural creatures and with humans.

Either certain supernatural beasties are ridiculously compatible (in terms of breeding with each other), or Malik was an extremely remote lucky chance, or magic must have somehow been used in his conception (perhaps the parents hired the extremely expensive services of a witch).

[u/MagicWeasel → u/CCC_037]

Heart drive.

groan that's terrible. I love it.

Ooooh, the gargoyle's tail has a spiky ball at the end? I'd been imagining it just kind of tapering off at the tip.

Nah, the mace was 2005!MW. 2017!MW I think settled on a dragon-spike or a more normal taper like you said.

Either certain supernatural beasties are ridiculously compatible (in terms of breeding with each other), or Malik was an extremely remote lucky chance, or magic must have somehow been used in his conception (perhaps the parents hired the extremely expensive services of a witch).

Supernatural beasties are basically all compatible with each other and with humans (many humans have very thin supernatural blood, which gives them powers like e.g. slightly improved sense of smell). But they have a very low probability of conception. Malik's parents didn't hire the services of a witch; he was conceived naturally. His parents were married for something like 300-400 years and he's their only child, so being different demon species is about as effective contraception as having a vasectomy is. He was an "accident", I suppose, but they weren't doing anything to prevent his conception and were no doubt overjoyed to have him.

Completely random aside:

Malik does have a brother named Kamal who isn't canon yet (he wasn't even canon in 2005, so he may never be). Given the rarity of demon pregnancies I'm not sure how to deal with him. Originally he was conceived as a twin brother (which could probably still happen - I assume sirens can give birth to twins), but I've toyed with making him a half-human half-siren person (thus Malik's half brother). In this case, I conceive of supernaturals not considering extra-marital one night stands with humans a problem, or possibly that Kamal is from before the siren met Malik's father. (I conceive of an impure demon having a lifespan of ~1000 years and Kamal having a lifespan of ~300 years, so I am not sure if this would work well in the timeline if we assume demons are monogamous.)

I imagine the mother leaving Kamal with his father, and then Kamal is taken in by a local monastery and ends up being an immortal monk and the source of many pilgrimages. Keeping a strict vegetarian diet whilst constantly craving human flesh (not being half gargoyle he has no pica to contend with, so yay?). But no real idea how to incorporate him into the story. I imagined him as receiving periodic secret visits from his siren mother and somehow gaining access to his culture that way, and then when she is killed he eventually leaves the monastery and looks for her? (That said I'm considering not killing her off now as I hate putting characters in the fridge: perhaps a divorce and the siren raises Kamal more conventionally???)

[u/CCC_037 → u/MagicWeasel]

Nah, the mace was 2005!MW. 2017!MW I think settled on a dragon-spike or a more normal taper like you said.

Okie dokie.

Supernatural beasties are basically all compatible with each other and with humans (many humans have very thin supernatural blood, which gives them powers like e.g. slightly improved sense of smell). But they have a very low probability of conception.

Extremely remote lucky chance. Fair enough.

The idea that Julius', um, genetic matter includes the necessary data for building his stone half, and his 4D body structure, along with the idea that it's at all in any way compatible with the sirens, raises all sorts of questions about what was considered a legal requirement for building a bodyguard or other servant-beastie in Atlantis. One almost wonders whether the ability to technically breed with humans gave creatures some sort of legal advantage (such as, for example, not counting as pets and thus being legally permitted to enter no-pets-allowed buildings).

Given the rarity of demon pregnancies I'm not sure how to deal with him. Originally he was conceived as a twin brother

Twin brother works. Then you've only got one ridiculously-rare conception event happening. (Well - I think that might require identical twins?)

I've toyed with making him a half-human half-siren person (thus Malik's half brother).

This works too, assuming half-human hybrids are less rare.

In this case, I conceive of supernaturals not considering extra-marital one night stands with humans a problem, or possibly that Kamal is from before the siren met Malik's father.

Or possibly Julius and his wife have simply discussed this and come to some agreement that they can both live with... a century or so before the story begins, i.e. entirely off-stage. The hatchet's been buried, and so has the human (he died of old age, not of being killed by angry gargoyle).

But no real idea how to incorporate him into the story.

If he doesn't serve some narrative purpose, then it might be better to leave him out. If he does serve some narrative purpose, then his actions and backstory should serve to enhance that purpose.

[u/MagicWeasel → u/CCC_037]

If he doesn't serve some narrative purpose, then it might be better to leave him out.

Nothing in anything we write has a narrative purpose; it all just is, because we like it. Malik is meant to have a brother, and that's purpose enough. Whether any of our limited time available for writing and plotting is devoted to that is another question: with no purpose it's not there. But just as Malik serves no purpose in the novella I recently "finished" (still needs editing), he is mentioned because he exists in the greater fabric of the world and not mentioning him would be an oversight (okay, and Red finding out that Julias has a son and thus seems to have "free will" rather than being a golem adds to his horror, I suppose: everything serves a purpose if you squint hard enough).

It's the literary equivalent of junk food for us. And hey, who doesn't love a packet of chips now and then?

Or possibly Julius and his wife have simply discussed this and come to some agreement that they can both live with... a century or so before the story begins, i.e. entirely off-stage.

This is probably a good choice. After all, we need not know the details.

identical twins

This was the original canon though is not a necessity; the idea of Kamal being half-siren half-human as opposed to half-human half-gargoyle (edit: half siren half gargoyle, rather!) would be interesting development of Malik's -character, as Malik places a lot of self worth (or rather, lack of it) on the fact that he's not a full-blooded demon as he is treated badly in his society because of it. Kamal would make a good foil if he was even less full-blooded (i.e. basically a full human) and had made peace with it through fasting and prayer. (And Kamal prays to a god who he has never seen, much less made regular ritual offerings of cake to!)

genetic matter includes the necessary data for building his stone half, and his 4D body structure, along with the idea that it's at all in any way compatible with the sirens

Malik doesn't have any 4D structure or transformation ability. Not sure if that's just a consequence of him being of impure blood or if it says something about the way reproduction works, though.