Berserker Armor

Equipped creature attacks each combat if able.
Whenever a creature is destroyed by a spell or
ability you control, untap equipped creature it
gains indestructible until the beginning of the
next endstep. If this is a combat phase, there is
an additional combat phase after this one.
Equip-Sacrifice four creatures.
"The previous owner of the armor was devoured by
it's steel teeth."