Sergay really sucks, sending Nina to Nagi then betray him with Arika. Although I think he also did that with Nina's safety in mind. If he betrays Nagi with Nina then Nina would be in harm's way. I guess Sergay never expect Nina to pull a meister robe out of nowhere.
The whole epi 17 just don't work for me. I did not feel for anyone in this episode. I guess I just have to accept the facts that crap happened, yet "train wreck" it ain't (meaning boring).
I just hope Natsuki will carry the show in epi 18 with her funny antics eheheh