Havi, the All-Father (ACR-056) [Assassin's Creed]

As long as there are four or more historic cards in your graveyard, Havi, the All-Father has indestructible. (Artifacts, legendaries, and Sagas are historic.)
Whenever Havi or another legendary creature you control dies, return target legendary creature card with lesser mana value from your graveyard to the battlefield tapped.