Celithe, Raven's envoy

{b/g}{p/b}{p/g}
Create legendary aura named Necrotic Form and attach to Celithe. Necrotic Form gives +3+3
and totem armor
{x}{p/b}{p/g}{t}
Put target creature card with mana cost x,
onto the battlefield under your control,
this ability costs y less where y is the total life
you've lost this turn
Pay 10 life: Untap Celithe, Raven's envoy