Alina's Mercy

Ward: Discard an instant or sorcery

Alina's Mercy's power is equal to the number of instants and sorceries in exile and in all players' graveyard

Barred from death - You may cast Alina's Mercy from your graveyard by discarding an instant or sorcery from your hand or exiling an instant or sorcery from your graveyard in addition to paying it's mana cost.