How to reform a toxic player mid game.

I just played a game where I was filled into adc, and my jungler was non stop flaming everyone. I kept calming him down, and he wouldnt budge, and the I said the magic words.

"If we win this game and you stop flaming, I will gift you skin"

After this, he immediately stopped flaming, and we won. I didn't gift him the skin. It sounds really douchey but it worked.