Evil Undead Fiery Undead ... Thing

[Grogg of the North]

Last session I sent my players to the abyss. As they traveled the 507th layer, the paladin in my group went up against a Thunderbeast. In a stroke of bad (good?) luck, the Thunderbeast rolled a few twenties in a row and did near max damage on the critical damage. Enough damage that I would have turned the PC into a smear within in the first few minutes of play with no easy access to magic to raise him. I gave him a choice. He could survive the hit but the Thunderbeast essentially, eats his sword arm. The player, eager to play something weird like that, continued to adventure with his one armed paladin.

Now, the party retrieved the eaten arm from the Thunderbeast's gullet, decided they didn't want to carry it with them afterall, and set it on fire before heading on their way.

I'd like for later on in their adventure for the evil of the abyss, combined with the lost paladin arm, to spew forth some sort of monster to fight the PCs. Now, I could make a big bad dark knight but that's easy and a little boring.

I am looking for suggestions on monsters, templates, classes, anything thing to make this encounter memorable. The party is about to hit level 11 soon and I plan for them to be around 12 when they finish up their planar camping trip.

 

[Celebrim]

I'd stat it up as a unique Effigy (Monster Manual II), by reducing size to Small, dropping CHR and INT by 4, rolling down the HD to say 20, and giving it a single attack per round. That should drop the CR from 17 down to about 12-13, making it a more reasonable foe. The Infuse attack is also particularly applicable to the backstory with the Paladin.

 

[Grogg of the North]

I went with your suggestion and everyone had a blast last night as the effigy showed up. As soon as the effigy started to attack the party threw up defensive magics to stop the possession ability. The party also blew threw a lot of homework rewards to ensure that no one lost any levels as well.

When the effigy died at the end I had it leave behind the paladin's severed hand. Not sure what to do with it, the party picked it up and tossed it into the paladin's pack. I think I need to have some more fun with that.

 

[Dandu]

Either make it strangle him in his sleep, or turn it into Thing.