Cloth Armor

Whenever a source would deal combat damage to armed creature, prevent 1 of that damage.
Arm {0} (You may cast this card from your sideboard. {0}: Attach to target legendary creature
you control as a sorcery. When a legendary creature you control enters the battlefield, you may
arm that creature as an instant. As long as this ability is on the stack, your opponent can't cast spells or activate abilities.)