S4·E7 Jinx

Mikail Mxyzptlk, a foreign exchange student and bookie, has the power to control others and uses it to sabotage football games, including the one Clark is quarterbacking. Clark and Chloe figure out his secret, but he threatens to kill Chloe unless Clark throws the next game. Mikail came to Smallville via LuthorCorp, and Lex will do almost anything to learn his secret.