Vampiric Healing

Spell stack {w}{b} (You may cast this spell as a
sorcery for {w}{b}. If you do, place it face down on
the battlefield as a 2/2 creature with; When you
cast another non-creature spell, you may flip this
spell over and cast it for its spell stack cost.)
Gain X life, where X is the amount of
damage dealt to another player this turn.