Argentum Armor

Artifact — Equipment

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip

2011-01-01:
The second ability triggers and resolves during the declare attackers step. The target permanent will be destroyed before blockers are declared.
2011-01-01:
You may target any permanent with the triggered ability, not just one controlled by the defending player. If no other player controls a permanent, you must target one of your own.