>>712872002Kris summoning (Us) has the best narrative payoff. He has some nearly-impossible goal in mind, but he learns that by making a pact with some otherworldly being that never accepts defeat, he might be able to succeed. He'll lose a ton of his self-control and do a lot of things he'd never do as himself, but the risk is worth it to him. Only now he's second-guessing the deal and has become resentful towards (Us), so he treats us as an unwelcome parasite.
I don't know if that's what Toby will do, but that's what I would guess.