The prince is trash, I hope redeems himself in the future but now he is trash! How can he see what he's future wife is doing to her sister, treating her as a maid and still stand by her side till now and even asking his father for the trail.
@yavinta I think her family sort of knew she was smart and had an inferiority complex so they taught her difficult things to make her feel stupid. But as we can she must be a genius which made the teacher feel inferior to her and thus hate her.
@UnknownSaint111 she didn't save her, she saved herself. If the younger sister has powers then she will be the one to suffer and eventually become a sacrifice.
It's all fun and games until a super powerful adventurer (team) with a hero complex decides to conquer his tower, kill all it inhabitants for guild quests and tries to kill him for being a tower lord / dungeon master.
With Kassia's abilities and the mage's transfer magic they just need to use guerilla warfare to earn time while assassinating key figures from the Emperor's and first prince's faction.