At this point he's just embarrassing himself, sure he can compete against Hyun internally if he wants as it is a competition but he shouldn't speak to him like that, Hyun is still a kid(in appearance at least). I don't understand why people don't do things for themselves and their happiness (like Yang Chen he plays music cause he loves that it allows him to help other people) instead of uselessly basing your mood and worth off another person's achievements or does William just play music to be the best at it? For the recognition and praise?That's all? That's what makes him happy? If so that's kinda empty. By not taking care of himself he's being a burden to other people in the house cause they then have to look after him as they are on their own. He may feel it's unfair but the world has always been unfair and it was his own ego that led him to think that he'd always be the best everywhere he went.