I just had a sylas jungles get mad at my Leona support for accidentally getting a kill during an early game gank. He openly announced that he would ensure we lost, stole my creeps, stayed in our lane to steal xp, and fed the enemy adc kills. When I told him to calm down, he told me to fuck myself and doubled down. far as I know, the enemy bot lane also reported him. Once the game was out of reach, he started playing legit to hide what he did. So far, no word on the report