Karasu tends to look down on people he finds "mediocre". He is wary of his surroundings and is able to control and produce chemical reactions with those around him. He is intelligent but has a sharp tongue and never misses a chance to insult someone, whether friend or foe. He has his own rules that he forces upon others to make matches go as planned. He dislikes it when anything goes wrong, even if it doesn't make a big difference, so it looks to others like he is always complaining.