SOF2Fragger

Are you in the right format? Chubz uses Doom 2 UDMF.

I think you were only loading a text file, but no textures

Add the pk3 as a resource in Ultimate Doom Builder

Misleading title.

Have you tried UDMF? Ultimate Doom Builder has a slope tool that shows you "handles" on the lines, so you can slope more easily

Make your door open by sinking into the ground, so you don't need to add anything else.

If you want it weaker and slower, then that's fine.

BOSS is just the name of the sprite, not a flag. It's the Baron of hell

The default doesn't need to be there. Only the death state. Remove health and speed. That's what changed your monster. Edit Did you include your custom monster as a resource?

This shouldn't affect anything but the monster's death.

Decorate doesn't use semicolons. It seems you took the death state from zscript. I edited my previous post.

That semicolon has no place there. Remove it. Also, use the death frames of your new monster and reverse them so it rises from the archvile's corpse. You don't need the BOSS sprites in there. That's the Baron.

ACTOR EVOLVED_HELLKNIGHT : HELLKNIGHT 25099 { States { Death: BOS2 I 8 BOS2 J 8 A_SCREAM BOS2 MN 8 BOS2 O 1 BOSS O 1 BOSS NM 4 BOSS L 4 BOSS K 4 A_NOBLOCKING BOSS J 4 BOSS I 4 A_SPAWNITEMEX("BARONOFHELL") Stop } } Hope that helps. This turns the hellknight into a baron when you kill him. Try it and see if that's the effect you want

Your monster dies, then raises back as the new monster. No corpse left.

I would create a new monster that inherits from the archvile, but when he dies, there's extra frames in the animation, so you can add the new monster rising animation after that, then spawn the new monster.