Time Stone

Flash
When Time stone enters the battlefield under
your control, Return a creature card from any
graveyard to the battlefield under your control.
If at any point you lose infinity stone, sacrifice
that creature.
{5}: Gain Control of Infinity stone. Any player
may activate this ability
At the Beginning of your end step, if you control
all six infinity stones, exile them, then meld them
into "Infinity Gauntlet"