Somehow I think after the events of episode 26 and 27 that Sonia and Eden are going to bolt and defect at the first possible opportunity. Neither of them have much reason to stick around with and put up with their parents bullshit after all that was revealed and transpired in that climax and pretty much every reason to want to resist their increasingly shameless cruelty.
One of the reveals that did surprise me though is that Sonia was indeed the one that killed Soma's dad who was basically caught off guard in refusing to fight what he saw as a harmless child. She obviously acted on instinct and doesn't seem to have enjoyed the moment of the kill so much as have been traumatized by it, but I don't think that should give her an out by any stretch and I think if she and Eden were to defect they're going to have to do a lot to make amends and to get the saints to completely trust them. One has to wonder though how both of them can have normal human emotions while Mars is such an evil bastard. Maybe they aren't really Martians at all and were never his kids...I mean there's a lot that doesn't add up here about the Martian side of the conflict that I'm sure has yet to be completely revealed.
Oh and one other thing I noticed, what seems to be one of Umakoshi's trademark visual cues that also appeared a lot in Casshern Sins and was even the title of the opening song seems to make an appearance in this episode again. The Blue Flower (Aoi Hana).