[K Peculier]

I'm still hesitant to approve soul manipulation as you've described at this level of proficiency. Especially if it's just more of a negative RP hook rather than actually using it to actively cause trouble and being a dedicated antagonist which even then would most likely need to be in the hands of an Eventmin character at the least.

The use of spirits in combat and daily could already be a rather controversial ability to use as a negative hook although with how often player characters are able to manipulate the use of spirits already available to them mechanically in the name of skills/talents/traits it's rarely seen as anything negative in the larger roleplay community.

The soul is a lot more special and abstract and being an expert at utilizing souls is a bit too powerful for players to have without it being the actual art of necromancy which is another player applied ability that is not easy to get as it relates to the manipulation of souls.

If you're still key on doing this whole plot, you'll more or less want to apply for the power of necromancy to your character/s.