Joyeuse

Whenever a creature you control attacks you may tap target creature defending player controls. If a creature you control would die, you may pay life equal to its power and toughness combined to remove all damage from it, tap it, and put a -1/-1 counter on it. Once per turn you may discard a card to deal damage equal to its converted mana cost as damage to target creature.
Not a single blade can match one as this, and its color shifts thirty times a day.