Sangrophage

At the beginning of your upkeep, tap Sangrophage unless you pay 2 life.

Swamp

Death's Shadow gets -X/-X, where X is your life total.

Agonizing Syphon deals 3 damage to any target and you gain 3 life.

When Hidden Horror enters, sacrifice it unless you discard a creature card.

Target player draws two cards and loses 2 life.

At the beginning of your upkeep, you draw a card and you lose 1 life.

Whenever another creature enters, you lose 1 life.

When Slum Reaper enters, each player sacrifices a creature of their choice.

Return up to two target creature cards from your graveyard to your hand.

Flying
If damage would be dealt to you, prevent that damage and mill twice that many cards.