The Titan Guard

Begin the game with this card revealed.
You can only control one creature, under
you control at any given time.
You begin the game with a 10/10 colorless
artifact Mech token, with indestructible,
defender, deathtouch, lifelink, vigilance.
Control of it cannot switch, and if it leaves
the battlefield, you get another immediately.
Your token can block any number of
creatures, and for other players.
Win: Eliminate a player that attacked.