Havi, the All-Father has indestructible as long as there are four or more historic cards in your graveyard. (Artifacts, legendaries, and Sagas are historic.)
Sage Project — 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.
If Havi and another legendary creature you control die at the same time, Havi's last ability will trigger for each of them.
05-07-2024
wotc
Damage dealt to creatures remains on those creatures until the cleanup step or until an effect removes that damage. If Havi loses indestructible (probably because one or more historic cards in your graveyard left your graveyard) after having been dealt lethal damage earlier in the turn, it will die.
05-07-2024
wotc
In the rare case where a legendary creature becomes a copy of another legendary creature with greater mana value (for example, if Sakashima the Impostor is a copy of a legendary creature with mana value 5 or greater), then when that creature dies, if it's still a legendary creature card in your graveyard, Havi's last ability will be able to target it.
05-07-2024
wotc
Lands are never cast, so abilities that trigger "whenever you cast a historic spell" won't trigger if you play a legendary land. They also won't trigger if a card on the battlefield transforms into a card with the legendary supertype, the artifact card type, or the Saga subtype.
05-07-2024
wotc
Use the mana value of the legendary creature that died as it last existed on the battlefield to determine what may be targeted with Havi's last ability.
05-07-2024
wotc
If a permanent or a card in a graveyard has {X} in its mana cost, X is 0 for the purpose of determining its mana value.
05-07-2024
wotc
A card, spell, or permanent is historic if it has the legendary supertype, the artifact card type, or the Saga subtype. Having two of those qualities doesn't make an object more historic than another or provide an additional bonus—an object either is historic or it isn't.
05-07-2024
wotc
An ability that triggers "whenever you cast a historic spell" doesn't trigger if a historic card is put onto the battlefield without being cast.
05-07-2024
wotc
Some abilities trigger "whenever you cast a historic spell." Such an ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.