Wizard of Time's End

Flash
Split second (As long as this spell is on the stack,
players can't cast spells or activate abilities that aren't
mana abilities.)
Exploit (When this creature enters the battlefield, you
may sacrifice a creature.)
When Wizard of Time's End exploits a creature,
you may cast spells as though they had flash
until end of turn. Spells you cast this turn have
split second.