A servitor is a thoughtform formed of your own mind, it shouldn’t clash with anything.
You can create a servitor for pretty much anything. You could house it in your instructors appartment or a possession. I would rather have it attach to my target though.
There’s a pretty good step by step guide here on how to ceate a servitor:
Mr. Kendall posted an awesome step by step guide on his youtube where he creates a baneful servitor himself