I liked the twins, specially Mizuno. And its nice (althought a bit cliched) to have a 'good' guy among the bad ones. Seems the intelligent twin (forgot her name) is in the Glittering Crux in order to lead them away from her sister.

With Mizuno confirmed as a Maiden... I guess that the class president from Glittering Crux is really the 4th one, after that bus scene last episode.