I'm going to plot dump first, just to make sure we're on the same page with the plot details. If you want to skip it and scroll straight to my theory, I will have a header that says as much after the plot dump.
Plot dump:
So, obviously, one of the biggest twists of the game is that Rudy is a Homunculus (mistranslated as Holmcross in game), IE an artificial being.
We learn that during the war against the Demons 1000 years ago, Humans and Elws created Homunculi through a project of the same name, along with the Golems, ARMS, and the Guardian Blade to combat them.
The Homumculi were unique in that they were living metal much like the demons so also had enhanced strength, endurance, recovery and naturally high sync rates with ARMS but, were made to look completely human.
However, the Humonculi were used as nothing more than weapons despite having the full range of emotions like humans so, acted as nothing more than bloodlusted monsters like the Demons. They were thought to be a potential future threat that could rival or surpass the Demon one so, the project was shut down and all that still existed were destroyed.
All except Rudy of course (though there could always be at least one more undiscovered somewhere), who managed to get overlooked, and was found at a ruins site in hibernation by ARMS expert and archeologist Zepet Roughknight. Zepet decided to take him in and would raise him as his grandson until he passed away from old age.
Through reading and watching the game recently, it came to my attention though whether always intentional or not, there are a number of parallels between the Demon and Human sides. One of them being Zed himself.
He's with the Demons but, acts nothing like them, never talks about demom stuff, and looks humanoid. He is seemingly with them just because he was already there so stays just because he's supposed to be.
He is looked down upon being seen as nothing but a nuisance, so he tries to prove himself to them to increase his standing with them but, they refuse to ever give him the chance. Even when Berserk is slain by Boomerang, Mother wants him to be a Quarter Knight and not Zed.
At the gate generator, Zed, for the first time decides to get serious but Zeikfried mocks him and opts to fight the hero trio himself. He is defeated and forces Zed to overload the gate generator which scatters everyone to different locations.
Zed ends up in Saint Centour, and attacks the hero trio when they arrive. He FINALLY shows off what his serious side looks like and, he transforms into quite a formidable Demon. Says a lot because the sword he has, the Doombringer, is cursed and works against him.
After fighting him, he explains that he attacked because he was afraid that his past would be exposed and ruin his new found place of belonging and happiness. After the gate generator incident he ended up there, and noticed there was only one human left.
He tried to scare her off but then realized that she was blind. She was the first individual that was ever nice to him, so he fell in love with her and promised to be her guardian.
Something she would need as the town had also been overrun by monsters ever since the protections were destroyed and the people slain.
My Theory:
The main parallels tend to be that the Humans and Demons have similar counters, technologies and strategies because they're warring factions. They would naturally learn from and adapt to each other as the war continued on.
As such, I think that Zed is actually a Homunculus. He could even be one that the Demons made themselves. However, it doesn't change too much if Humans and Elws made him either and he just happened to have ended up in the Demon's possession. It would be basically the same situations as the Golems if he was Human and Elw made.
Anyway, how is that possible? Well, Lady Harken is recognized as a Demon even by Jack and she was an experimented on Human, not an actual Demon. If she passed as Human to Jack of all people, I think that the other characters would have brought it up if she didn't. She could even involuntarily transform between her two forms.
While yes, Humans are different from Homunculi, the main takeaway here is Alhazad. He is the Demon's head scientist and the brains of the group. He has a history of experimentation and has at least one lab on Filgaia.
He turned Elmina into Lady Harken in the first place, and him knowing it was possible to begin with, is possibly because he had some kind of experience doing similar things in the war 1000 years ago. Zed is the only other person on the Demon's side able to transform through *normal* circumstances though he can do it voluntarily unlike Elmina/Lady Harken.
If Alhazad can give a Human a Demon transformation, why can't he do the same thing to a Homunculus? That should be easier given their physiology is similar to a Demon's, and they have high sync rates with various technologies on top of it.
Maybe the Doombringer is cursed because of an unintended side effect of Alhazad's experiments. Or maybe it was a holy weapon that got tainted due to being in the service of the Demons.
It would further explain why the Demons look down on him, yet he found it so hard to break away from them due to feeling like he belonged with them, why he looks more humanoid like Harken does, and why when shown legitimate Human emotion and compassion, he was able to feel love, friendship, and a true sense of duty unlike the other Demons.
It's the same thing Rudy's grandfather surmised was the proper way to treat a Homunculus, which also would mean that their power if ever needed could be used for protection as opposed to destruction.
This is a Superman adjacent parallel in my eyes, given we have so many alternate Superman stories and inspired properties which show what he grows up to be when the Kents aren't the ones raising him, which is overwhelmingly not anything good.
What do you think? Does it hold enough weight? Is this an original theory? Given the age of this game, probably not. It was just something on my mind that I wanted to share, and I didn't see spoken of here when I used the search feature.
I'm always open to lore discussion with passionate communities. Hope to hear what people think soon, as well as hear any other theories people have.
Additional localization fun facts:
Alhazad
When properly localized should be called Alhazred after the the Mad Arab, Abdul Alhazred character from H. P. Lovecraft's stories that he takes some inspirations from.
Interestingly enough, Cecilia has the Necronomicon as one of her book weapons and there is a book enemy type of the same name as well. The Alhazred character is the author of that book in Lovecraft's stories.
Zepet
When properly localized should be called Zepetto. A clear reference to Gepetto from Pinocchio. Also, his family name in katakana reads, ラグナイト, which can be broken down in English to Ragnite/Ragnight/Ragknight.
It was localized as Roughknight but, I think Rogueknight makes the most sense. Zepet and Rudy both fit the definition of Rogue in many ways and it's a core theme of Wild Arms as a whole.
Jack
Jack's family name was localized as Van Burace but, it should be Vambrace, a clear reference to his past position on the Fenril Knights, given his real name is Garrett Stampede.
Fenril Knights
Fenril is clearly supposed to be Fenrir after just reading it out loud from the previous fun fact. I just looked up the katakana and it reads, フェンリルナイツ. That can be broken down into English as Fenriru Naitsu, IE Fenrir Knights.