Command - Rigor Mortis: Any of this is possible with Erik; his mutation doesn't allow him any kind of supernatural resistance to mind control. He is canonically a ludicrously strong willed person though, so it might be harder? And then he'd be all RARGH REVENGE and it would just be messy and sad. :(

Path of Thorns & Hawthorn Barrier: Sure!

Feeding: If they get to be friends then I think if asked he'd just be like.../shrug. Because why not, it's not like it is going to kill him.

But uh, after he finds out what it feels like it would never happen again. XD His loyalties are. Weird.