The Beyonder

Hexproof

You may cast The Beyonder from your graveyard or from
exile.

Equipped creature gets +6/+6, hexproof and whenever
this creature deals combat damage to a player, you may
sacrifice The Beyonder. If you do, exile all nonland
permanents you don't control.

Reconfigure {6}({6}:Attach to target creature you control; or
unattach from a creature. Reconfigure only as a sorcery.
While attached, this isn't a creature.