I gotta say I really dislike Rei's insistence on the Seed of Caution (in the LN it's called the Seed of Contract, which makes more sense). Also, Elena seemed angrier with him about that demand here than in the LN, which is good, because it's a total fucking dick move. He took the job to protect them and now he's saying "swear an oath to me on your life or I'll leave you to die"? Those aren't the actions of a good person. It's like Superman threatening to kill Jimmy Olsen for knowing his secret that he's also Clark Kent - and being fucking serious about it. Rei did the same shit with that Milena girl or whatever and her whole party - and yet they act all chummy afterward, despite the fact that a slip of the tongue while drunk or under torture could kill them.