We have the key taken from Elis. We have all the Yuukas. The split Yuukas don't seem as powerful or awake as a whole Yuuka would be. Yuuka might even consider herself in the gang's debt if we restored her into a single whole (well, until she learns about her house anyway). And Chiyari can always bring her back... different.
Who would know if Chiyari nudged the behavioral dial before pressing start? Besides the monkey on her back, er, ghost in her backside. Mima did spend an awfully long time as pickle. What better revenge for a transformation than another transformation in turn? Yuuka's fate is in Chiyari's hands!
>>49567980
Team 3, you BAKAS. A city full of hostiles and you choose to slam a monster into the one building occupied by friendlies!
Well, Chiyari et al. are either in a reinforced section or this is occurring before the giant popcorn monster crashes into the building.