Intervention Pact

The next time a source of your choice would deal damage to you this turn, prevent that damage. You gain life equal to the damage prevented this way.
At the beginning of your next upkeep, pay {1}{W}{W}. If you don't, you lose the game.

Blood Crypt

({T}: Add {B} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. This land deals 1 damage to you.

Mount Doom

{T}, Pay 1 life: Add {B} or {R}.
{1}{B}{R}, {T}: Mount Doom deals 1 damage to each opponent.
{5}{B}{R}, {T}, Sacrifice Mount Doom and a legendary artifact: Choose up to two creatures, then destroy the rest. Activate only as a sorcery.

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Summoner's Pact

Search your library for a green creature card, reveal it, put it into your hand, then shuffle.
At the beginning of your next upkeep, pay {2}{G}{G}. If you don't, you lose the game.

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Amulet of Quoz

Remove this card from your deck before playing if you're not playing for ante.
{T}, Sacrifice this artifact: Target opponent may ante the top card of their library. If they don't, you flip a coin. If you win the flip, that player loses the game. If you lose the flip, you lose the game. Activate only during your upkeep.

Warrior's Oath

Take an extra turn after this one. At the beginning of that turn's end step, you lose the game.

One with Death

Alchemist's Gambit

Cleave {4}{U}{U}{R} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Take an extra turn after this one. During that turn, damage can't be prevented. [At the beginning of that turn's end step, you lose the game.]
Exile Alchemist's Gambit.

Blackcleave Cliffs

This land enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.

Slaughter Pact

Destroy target nonblack creature.
At the beginning of your next upkeep, pay {2}{B}. If you don't, you lose the game.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Pact of the Titan

Create a 4/4 red Giant creature token.
At the beginning of your next upkeep, pay {4}{R}. If you don't, you lose the game.