My guess is that she is going to fake a scene of the butterflies eating Cassis. She led the Pedelian people to a dangerous zone so when they die in a large number, she can fool her family that Cassis also dies among them. This way Cassis can escape and she won’t be harmed by her family. Probably...
I don’t agree with the comments calling her a sl*t because she is not. However, she is quite dumb and insensitive. Like I get it you might not realize Haruto like you, but why accept dating a friend of his that you barely know? Even if you don’t like Haruto, don’t act like he doesn’t even exist...
I don’t get why people think the naming is lazy when it is obviously inspired by the story of King Henry VIII and the names are a hint of how the characters are.