Sin, Spira's Punishment

Flying
Whenever Sin enters or attacks, exile a permanent card from your graveyard at random, then create a tapped token that's a copy of that card. If the exiled card is a land card, repeat this process.

Seedship Broodtender

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
{3}{B}{G}, Sacrifice this creature: Return target creature or Spacecraft card from your graveyard to the battlefield. Activate only as a sorcery.

Vanille, Cheerful l'Cie

When Vanille enters, mill two cards, then return a permanent card from your graveyard to your hand.
At the beginning of your first main phase, if you both own and control Vanille and a creature named Fang, Fearless l'Cie, you may pay {3}{B}{G}. If you do, exile them, then meld them into Ragnarok, Divine Deliverance.

Muldrotha, the Gravetide

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Cloud of Darkness

Flying
Particle Beam — When Cloud of Darkness enters, target creature an opponent controls gets -X/-X until end of turn, where X is the number of permanent cards in your graveyard.

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Ragnarok, Divine Deliverance

Vigilance, menace, trample, reach, haste
When Ragnarok dies, destroy target permanent and return target nonlegendary permanent card from your graveyard to the battlefield.

Cosmogoyf

This creature's power is equal to the number of cards you own in exile and its toughness is equal to that number plus 1.

Death

Return target creature card from your graveyard to the battlefield. You lose life equal to its mana value.

Life

All lands you control become 1/1 creatures until end of turn. They're still lands.

Life // Death

Neo Exdeath, Dimension's End

Trample
Neo Exdeath's power is equal to the number of permanent cards in your graveyard.

Exdeath, Void Warlock

When Exdeath enters, you gain 3 life.
At the beginning of your end step, if there are six or more permanent cards in your graveyard, transform Exdeath.

Exdeath, Void Warlock // Neo Exdeath, Dimension's End

Fang, Fearless l'Cie

Whenever one or more cards leave your graveyard, you draw a card and you lose 1 life. This ability triggers only once each turn.
(Melds with Vanille, Cheerful l'Cie.)

Jenova, Ancient Calamity

At the beginning of combat on your turn, put a number of +1/+1 counters equal to Jenova's power on up to one other target creature. That creature becomes a Mutant in addition to its other types.
Whenever a Mutant you control dies during your turn, you draw cards equal to its power.