Electro, Assaulting Battery (#76)

Type: Legendary Creature — Human Villain

Text: Flying
You don't lose unspent red mana as steps and phases end.
Whenever you cast an instant or sorcery spell, add {R}.
When Electro leaves the battlefield, you may pay {X}. When you do, he deals X damage to target player.

Set: Marvel's Spider-Man (#76)