Discussing Blood Magic in a different game made me wonder if the MC will ever do blood magic here. Sure, it can be super dangerous, little things like "killing you if you aren't careful", but I'm sure with the group he has they'll make sure he is able to use it responsibly, right?? Lessee, Metatron, Sarah, Celica and Aspasia and...uh that's it for "Responsible," Sam, Ashley, and Maya are definitely NOT, and I'm not so sure on Siofra or Ina either... ummm maybe it's better he doesn't learn it? If he's anything like my luck, there will be "it wasn't supposed to do that..." a lot (I have horrid luck).
I do wonder how much of Ashley's rather blatant flirting is "succubus related" and how much is just Ashley. Sarah is a lot more quiet in her flirting and when she does flirt she almost seems surprised, whereas Ashley flirts, flirts some more, and then flirts again just it case it wasn't enough!
You mentioned that Ina doesn't see Kuril or Kanadros as friends, does she view them as mentors or something? Yeah, Kuril's a bodyguard, but you can be bodyguard and friend too. Maybe because it's because she is a princess she doesn't want to admit they are friends?