Holy Hand Grenade

Exile target legendary creature. Gain life equal to
it's covered mana cost.
"Once the number three, being the number of the counting, be reached, then lobbest thou the Holy Hand Grenade in the direction of thine foe, who, being
naughty in my sight, shall snuff it."
-A Reading from the Book of Armaments, Chapter 4, Verses 16 to 20