Thanks! With that in mind I managed to find 2 more in a new playthrough, but I'm still struggling with the first and the last one. Could you please give me a little hint about them?
For the first one: There's something slightly out of place near the Old Hideout.
And the last: If you've bought something from the third tab of the Shop and used it on an Undead, you might have seen the warning that each Undead can only have one of those given to it. But there's a certain Undead you already have that doesn't have that limitation and can take multiple... which can lead to encountering the last Undead.
I'm sorry to disturb you again, but I couldn't find the first one. Twice 40 turns were spent for level near the Old Hideout, and levels after it were also replayed. Looks like every single tile were checked. However, all that I could find was a leather pouch in the bushes. Can I get another hint?
For players that have read up to this point. If you have any questions about the other elements of the game, I could try to answer them so as not to distract Styx again.