BBEG match up

[Arcane possession]

I have been asked to create a session for a bunch of level 6 PCs a barb, a magus, a ranger, a paladin, a rogue and a NPC possible sorcerer. I am going for the typical haunted/evil mansion with a few low level haunts and so far 2 faceless stalkers to try and infiltrate the group when it splits. The main focus is undead with a few abberation or monstrous humans but I am struggling to decide on the BBEG who is responsible for this horror should it be an incorporeal or witch/necromancer. I prefers the incorporeal due to age of the horrors but I have no idea which would appropriate or adequate for the group. So any advice or thoughts are welcome.

[wraithstrike]

What level are they?

[Cap. Darling]

wraithstrike wrote:

What level are they?

6

[Arcane possession]

Yes level 6 I'm hoping to find either a level appropriate necro build or a suitable incorporeal matching a necro build for them to fight.

[Dosgamer]

I built a cleric of Urgathoa out of a basic shadow and she turned out to be a nasty bbeg. You might go that route if it is thematically appropriate. Alternatively, you could create a shadow sorcerer of some sort. Good luck!

[Arcane possession]

If I was to create a cleric what level should he be and for reference against the PCs I've described what class would you throw at them in an alternate battle that would challenge them maybe two or three classes be needed.