Nuclear Response

Deal X damage to target player and his creatures,
where X is the amount of mana used while
playing this spell. Every other target, including yourself and your creatures, take half damage
which is rounded down. Place any lands used to
cast this card into your graveyard.
If both you and your opponent reach 0 life points
or lower because of this spell, you lose the game.
"I am become death, the destroyer of worlds."