Kusa is a competitive player who has moved into one team and another. He keeps moving and joining other teams for lots of reasons. First, he was an S rank player and joined a team. He was their slayer player, but he realized that playing with this team, couldn't improve him. Because he thinks that he's better than any of his team members and his opponents. He always won the game, got the most kills, the most assists, the least deaths, etc. So he moved into another team. That team putting S+ as the requirement. He was an S+ player at that time so he joined in. In this team, he could see his teammates were better for the skills of individuals, but they lacked skill for team fight a lot. This makes him frustrated and blaming his teammate a lot. Even in a tournament, he and his team argue a lot. Someday, his teammate got enough of him and kicked him away. Kusa at first thought it would be fine and he could join another team. Turns out, his bad reputation spreads so fast. Every time he wants to join a team, he gets rejected immediately. It needs 3 months for him to reflect on what he did and once again, try to join any team that wants to accept him. He asked 4 teams and they're all rejecting him. Until Toni and the others finally accept him.