So I'm looking for some advice on an encounter idea I have. The party is fairly high level and really well equipped. For months now (both real time and game time), they have been outsmarted by a Succubus. This Succubus has some levels and has been using her natural abilities and spells to really be a pain, but never engage. The highest point was when she played the victim, fooled the cleric, got him to give out some important information, drained a few levels (wink wink, nudge nudge), and then teleported away. In encounters since then, the Cleric and Succubus have had some really good dialogue. (By good, I mean awful 80s sword and sorcery style dialogue. She always calls him "Lover" now. The Cleric is a good sport and great player, and he's sort of adopted the attitude of "So I have this crazy ex who just can't let it go".)
Anyways, they're about to track her down to her lair and they're ready to throw everything they have at her. Now I was thinking of having the big surprise be her "new boyfriend", a charmed or whatever Planetar who fights to protect her. I think it'll be an interesting switch up for a good party that has done a lot of demon hunting.
So I'm looking for some ideas of how I should make that happen. The Angel has just fallen? If so, should I switch everything over, so it's alignment is evil now, it has DR/Good, etc? If so, that doesn't seem too different from the standard evil stuff they fight. Should I make him under some spell? What spell or effect should it be? That seems to work fine until somebody in the party goes "this doesn't seem right, dispell magic" and now my boss fight has gone from a challenge to "well, we have a pissed off Planetar on our side for free now". That'll happen about a round in, maybe 2, considering how smart this party plays.
Just looking for some suggestions or how other people would run this. I'm totally not opposed to just saying "this is a special bad guy, not straight from the bestiary" and having all sorts of weird stats on him.
