Spoiler for Episode 16 (and a bit on 17):
Damn, there's hints for a Face Heel Turn for Regina.
Then again, there's not enough resistance from the Doki Doki members against Regina, even after knowing that she's the Selfish King's daughter.. Feels sad that only Makopi is the only one who takes her seriously, and Rikka pretty much backed down without a fight.
But Episode 17 is really where everything starts to heat up... Regina having grasp of a Royal Crystal won't be good for the team. (Eyes glowing red? Sh*t's going to hit the fan)