Heads Up for Banru! <3
In one word, Banru is a douchebag.
Outwardly he'll be kind and gentlemanly to everyone. Inwardly, though, he's a selfish scheming bastard that doesn't care about those around him and will use anyone and everyone to reach his goals. In other words, LIE ABOUT EVERYTHING. However, he is also capable of empathy and even kindness, though both are buried so deep under layers of LOL ASSHOLE that they're almost nonexistent. He's been extra evil while in this game because he wants to win no matter what to get back to killing the Big Bad in his universe (in which he is, bizarrely, the hero), though that won't apply to Yako when she gets his personality, since she isn't getting his memories.
Yako could gain some magical knowledge, though she will not be able to use any complex spells which require symbols. In other words: Yako can change her hair pink, create a small flame in her hand, do a gust of wind, ect. Small stuff. However, she cannot hurl fireballs or start gale force winds.