Yuumi, Magical Principal

Bestow {x}{g}{u}{w} (If you cast this card for its
bestow cost, it's an Aura spell with enchant creature.
It becomes a creature again if it's not attached to
a creature.)
Enchanted creature gains lifelink and +X/+X
where X is the amount of mana
spent to cast Yuumi, Magical Principal.
"Okay, okay... we can make this work!"