Davriel, the Demonologist

Lifelink
{3}{b}{b}{t}: Exile target creature card from your graveyard. Reveal cards from the top of your
library until you reveal a demon creature.
Put it on the battlefield.
Whenever a non token demon you control dies,
you may exile Davriel, the Demonologist, then
return it to the battlefield transformed into
Davriel, Lord Greystone under its owner's
control.