Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Immolating Souleater

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

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Claim the Firstborn

Gain control of target creature with mana value 3 or less until end of turn. Untap that creature. It gains haste until end of turn.

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Dark Ritual

Pact Weapon

As long as Pact Weapon is attached to a creature, you don't lose the game for having 0 or less life.
Whenever equipped creature attacks, draw a card and reveal it. The creature gets +X/+X until end of turn and you lose X life, where X is that card's mana value.
Equip—Discard a card.

Hall of the Bandit Lord

Hall of the Bandit Lord enters tapped.
{T}, Pay 3 life: Add {C}. If that mana is spent on a creature spell, it gains haste.

Seething Song

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Devour in Shadow

Destroy target creature. It can't be regenerated. You lose life equal to that creature's toughness.

Rising of the Day

Creatures you control have haste.
Legendary creatures you control get +1/+0.

Phyrexian Arena

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

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Blood Celebrant

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

Unexpected Windfall

Rowan, Scion of War

Menace
{T}: Spells you cast this turn that are black and/or red cost {X} less to cast, where X is the amount of life you lost this turn. Activate only as a sorcery.

Diabolic Revelation

Search your library for up to X cards, put those cards into your hand, then shuffle.

Night's Whisper

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Blood Pact

Target player draws two cards and loses 2 life.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Tentative Connection

This spell costs {3} less to cast if you control a creature with menace.
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

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: Wall of Blood gets +1/+1 until end of turn.

Sting, the Glinting Dagger

Equipped creature gets +1/+1 and has haste.
At the beginning of each combat, untap equipped creature.
Equipped creature has first strike as long as it's blocking or blocked by a Goblin or Orc.
Equip {2}

Deepwood Ghoul

Phyrexian Lens

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

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Greed

Skirge Familiar

Rowan's Grim Search

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
If this spell was bargained, look at the top four cards of your library, then put up to two of them back on top of your library in any order and the rest into your graveyard.
You draw two cards and you lose 2 life.

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.

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap Staff of Compleation.

Font of Agonies

Whenever you pay life, put that many blood counters on Font of Agonies.
{1}{B}, Remove four blood counters from Font of Agonies: Destroy target creature.

Priest of Urabrask

When Priest of Urabrask enters, add {R}{R}{R}.

Priest of Gix

When Priest of Gix enters, add {B}{B}{B}.

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Rakdos Signet

Sol Ring

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.