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.

Kotis, Sibsig Champion

Once during each of your turns, you may cast a creature spell from your graveyard by exiling three other cards from your graveyard in addition to paying its other costs.
Whenever one or more creatures you control enter, if one or more of them entered from a graveyard or was cast from a graveyard, put two +1/+1 counters on Kotis.

Sidisi, Brood Tyrant

Whenever Sidisi enters or attacks, mill three cards.
Whenever one or more creature cards are put into your graveyard from your library, create a 2/2 black Zombie creature token.