Demon of Fate's Design (137) [Duskmourn: House of Horror Commander]

Flying, trample Once during each of your turns, you may cast an enchantment spell by paying life equal to its mana value rather than paying its mana cost. {2}{B}, Sacrifice another enchantment: This creature gets +X/+0 until end of turn, where X is the sacrificed enchantment's mana value.