Dark Ritual

Blood Celebrant

{B}, Pay 1 life: Add one mana of any color.

Feed the Clan

You gain 5 life.
Ferocious — You gain 10 life instead if you control a creature with power 4 or greater.

Transcendence

You don't lose the game for having 0 or less life.
When you have 20 or more life, you lose the game.
Whenever you lose life, you gain 2 life for each 1 life you lost. (Damage dealt to you causes you to lose life.)

Swamp

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Platinum Angel

Flying
You can't lose the game and your opponents can't win the game.

Forbidden Crypt

If you would draw a card, return a card from your graveyard to your hand instead. If you can't, you lose the game.
If a card would be put into your graveyard from anywhere, exile that card instead.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Harmless Offering

Target opponent gains control of target permanent you control.

Shared Summons

Search your library for up to two creature cards with different names, reveal them, put them into your hand, then shuffle.