The Reality stone

Shroud
{4}: You gain control of this artifact. Any player
may activate this ability.
{x}, {t}: Target creature gets +X/+X until end of
turn.
{x}, {t}: Create a copy of target permanent with converted mana cost X or less. Only activate if
you control 3 or more Infinity Stones.
{x}{x}, {t}: Up to X target permanents become
wastes. Only activate if you control 5 or more Infinity Stones.