Bond of Agony

As an additional cost to cast this spell, pay X life.
Each other player loses X life.

Tormented Soul

Tormented Soul can't block and can't be blocked.

Deathgreeter

Whenever another creature dies, you may gain 1 life.

Demonic Collusion

Buyback—Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Search your library for a card, put that card into your hand, then shuffle.

Death Cultist

Sacrifice Death Cultist: Target player loses 1 life and you gain 1 life.

Beseech the Queen

({2/B} can be paid with any two mana or with {B}. This card's mana value is 6.)
Search your library for a card with mana value less than or equal to the number of lands you control, reveal it, put it into your hand, then shuffle.

Swamp

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.