Darksteel Suit

Darksteel Suit is indestructible
Equipped creature is indestructible.
Equipped creature has vigilance and double strike, must attack each combat if able, must block each combat if able, and must be blocked if able.
When Darksteel Suit becomes unattached from a creature, sacrifice that creature.
Prevent all combat damage equipped creature would deal to players.
Equip Legendary Creature {3}
There can be no victory, and so I fight forever