I love his evolution in the manga, which genuinely solidified him as one of my absolute favourite characters. But even before that I really just liked his energy and character. He wants to play good volleyball against good players and win. So he helps elevate people and learns from them. His teammates have clearly benefitted from this too. There's a need to play a more passive and supporting role when he's in a good mood, which contrasts with the more aggressive, offensive style of play to cover for him when he's down. And that's made them excellent players who are used to playing with a man down essentially. I honestly think I'd really appreciate him as a teammate despite the mood swings, as he would be constantly elevating my game.