Ozma

When an Echantment enters the battlefield
under your control, you may pay {3}. If you do,
Ozma deals X damage to any target, where X is
the converted mana cost of that enchantment.
Ozma gets +1/+1 for every enchantment on the
battlefield.
If Ozma would leave the battlefield, you may
sacrifice two enchantments. If you do, Ozma
phases out instead.