Mizzix, Izzet Spellsplitter

Whenever you cast an instant or sorcery spell,
you may pay {x} and X life, where X is equal to its
mana value. If you do, that spell gains storm and
"When this spell resolves, exile it". Activate this
ability only once each turn
Exile Mizzix, Izzet Spellslinger: Return target
instant or sorcery card that you own from exile to
your hand. It gains "When this spell resolves,
exile it"