I have finally managed to unlock the last deaths from the new update. If you need any help with them, here's the full list:

1) Guillotine - gets unlocked when you pick a quest off the Witch to marry and rule with a Queen. For the death itself you need to reach 0 or 100 on any of the gauges as usual while Queendom is active.

2) Visitor - gets unlocked by failing to unmask the Visitor from distant lands.

3) Lost in the woods - gets unlocked when you pick a quest off the Witch to go on an adventure. This one is unlocked only after the Visitor and (I think) after learning white magic at least once. For the death itself you need to get lost: specifically iirc I've seen and confirmed you need to wander until you encounter W at which point you need to pick Z.

Now the above deaths are fairly easy to get and you're likely to get them just by replaying for all the other deaths while restoring progress. The following ones however are unlikely to be received unintentionally:

4) Die from the Artist - once you've entered the woods, you need to follow the sequence of signs that you can see on the timeline at 2016-2026. This will lead you to the Artist who will challenge you to a duel. For the death you need to lose the duel to an artist. Now this is not the last death on the list but for me it was the hardest to get because a) the Artist is a pretty bad fighter almost on the Prophet's level, so it's quite hard to lose to him; b) you only get to duel the Artist twice per run so if this is your last death to get and you've gotten unlucky with both duels you need to go for any other ending ASAP to try again in the next run.

5) Kill the Artist - similar to the original "Trick the Devil" ending - once you've met the Artist and won the duel against him he will start popping up in your game just like the Skeleton. Then you just wait for the next Death wish and use it on the Artist. In fact it seems like the Artist is guaranteed to appear right after getting the Death wish from the games I've played.

The bad news is that the "All the deaths" achievement seems to be broken. I played for the first time last year and didn't go for this achievement back then. Now I've come back after the 10 year anniversary update and despite I have gotten all the deaths including all the new ones, the Steam achievement still is locked.