Mistform Dracolich

Flying, deathtouch, prowess
When Mistform Dracolich enters the battlefield, put a phylactery counter on an artifact you control.
As long as you control a permanent with a phylactery counter on it, Mistform Dracolich has indestructible and "Pay 4 life, Sacrifice another creature: Exile Mistform Dracolich, then return it to the battlefield under your control."