The omnipotent trio

Changeling, Indestructible, Reach
If you don't discard two cards every time
The Omnipotent Trio attacks, then destroy this card
{u}{u}{u}{x}:This card can turn into any card
on the battlefield, in the graveyard,
or in exile for x turns except its a legendary creature and a shapeshifter including
all of its other types.