Empty the Pits

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Create X tapped 2/2 black Zombie creature tokens.

Open the Graves

Whenever a nontoken creature you control dies, create a 2/2 black Zombie creature token.

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Bastion of Remembrance

When Bastion of Remembrance enters the battlefield, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.