Timeswiper

Flash (You may cast this spell any time you could cast an instant.)
When Timeswiper enters the battlefield, end the phase. (Exile all spells and abilities on the stack. Skip all steps except for the cleanup step. If it is the ending phase, 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.)