I play in my school's D&D club and our first year was last year. During that first year, one of my fellow players rolled a sorcerer with high charisma (17) but low intelligence (8). He roleplayed his character however as if his intelligence is a 2 or 3, where his character knew nothing, messed up plans on purpose, and frequently injured his teammates with AOE spells.
When that school year ended, I thought I was rid of this character. But when the club reformed, he used the exact same character again and has gone even further to be annoying and mess people up.
How can I get him to contribute to the team or get him to stop acting obnoxious?