He is cold, doesn't like to talk, doesn't care about anyone or anything and never shows his emotions. That's the character of the frost knight. In reality, he is a friend-who-is-not friend of the Sun Knight, and likes to prepare sweets for him. Creus even mentioned that he'll make a good motherfather. He is a tough opponent, really good at swordmanship. He also hates to waste food.
Vova
