A valkyrie would be tough -- the way we see her, she's got a refresh cost of -13, at least.
A jann might be easy, might not be -- we know very little about what their capabilities are.
A ghoul is technically an option with a refresh cost (as we estimate it) of -7 ... but dude, "Ghouls can go through 40 to 50 lbs of meat a day, preferably human." So, ew. I'd find it a tonal mismatch for my own game, but that doesn't mean you can't lobby your own GM. (Meat bribe?)