A couple of thoughts for review/suggestions.

How about instead of a "daemon" coming out of the painting, what comes out is a transformed Andreas Bruner. He's back to claim "his manor" and doesn't take kindly to interlopers. Piersson's "revenge" isn't simply corrupting and killing him, it's turning Andreas into a Chaos Warrior. After a year's gestation, Andreas has been transformed and is ready to be summoned out. The beastmen are still attracted to a "natural leader" for them and the "bad outcome" is a Chaos Warrior welding beastmen herds into a force in Reikwald.

The Players will be well along in 2nd career by the time they face this foe - though I might tweak him to be a less dangerous Chaos Warrior. A painting of Andreas (with Piersson in background as loyal servant) should be in manor (so PC's know what he looks like).

The adventure will be between Gathering Storm and Edge of Night (assuming I decide to run it), the heroes will either get along with Rickard A. and actually start along his Edge of Night track, essentially having him as a patron and being at ball for that reason, or will end up antagonized to him and he to them, needing to fear him growing in power and thus aligning with another family to stop him.

Rob

It's a preaty good idea. Mutated/reborn Andreas leading a small force (the Cult) and able to tame/control a Beastmen herd too, that would wreck the area preaty well. Slaanesh oriented Chaos Cult-Warrior ?

Maybe you also need to forbid the interruption of the ceremony (transformation / summoning) as the original scenario allows, so that he is in play for sure. Some tinkering here to be done. If no sacrifice (in the undergrounds), the Chaos Warrior is super weak (versus the original Chaos Warrior), if ceremony is done ok (including Morrlieb exposition on the roof), he is just a weaker version.

If your group is tough in their second career (combat tough), maybe turn the basic Cultists (or half of them) into Cult Mutant and make the Cult Leader (Piersonn) also a Mage (basic Wiz cards + 3 Chaos Spells, rank 1-2). That and a lowered Chaos Warrior would be worth a Rank 2 group. The herd can also be hard to deal with if both forces join.

Thanks for the suggestions.

Rob