Dude

The next time a player's life would change by 20 or more this turn, instead, end the turn. (Exile all spells and abilities on the stack, including this card. The player whose turn it is discards down to his or her maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)
Split Second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)