Fire Covenant

As an additional cost to cast this spell, pay X life.
Fire Covenant deals X damage divided as you choose among any number of target creatures.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Talisman of Indulgence

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

Moltensteel Dragon

({R/P} can be paid with either {R} or 2 life.)
Flying
{R/P}: This creature gets +1/+0 until end of turn.

Treasonous Ogre

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Pay 3 life: Add {R}.

Blood Celebrant

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

Descent into Avernus

At the beginning of your upkeep, put two descent counters on this enchantment. Then each player creates X Treasure tokens and this enchantment deals X damage to each player, where X is the number of descent counters on this enchantment.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: This creature gets +1/+1 until end of turn.

Sol Ring

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Dark Ritual

Greven, Predator Captain

Menace
Greven gets +X/+0, where X is the amount of life you've lost this turn.
Whenever Greven attacks, you may sacrifice another creature. If you do, you draw cards equal to that creature's power and you lose life equal to that creature's toughness.

Doom Whisperer

Flying, trample
Pay 2 life: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Rakdos Signet

Immolating Souleater

{R/P}: This creature gets +1/+0 until end of turn. ({R/P} can be paid with either {R} or 2 life.)