Mana Tithe

Counter target spell unless its controller pays {1}.

Cartouche of Zeal

Enchant creature you control
When Cartouche of Zeal enters, target creature can't block this turn.
Enchanted creature gets +1/+1 and has haste. (It can attack and {T} no matter when it came under your control.)

Blood Celebrant

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

Dark Ritual

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Angel's Grace

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
You can't lose the game this turn and your opponents can't win the game this turn. Until end of turn, damage that would reduce your life total to less than 1 reduces it to 1 instead.

Marsh Flats

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

Arid Mesa

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

Thud

As an additional cost to cast this spell, sacrifice a creature.
Thud deals damage equal to the sacrificed creature's power to any target.

Not of This World

Counter target spell or ability that targets a permanent you control.
This spell costs {7} less to cast if it targets a spell or ability that targets a creature you control with power 7 or greater.

Godless Shrine

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

Scourge of the Skyclaves

Kicker {4}{B}
When you cast this spell, if it was kicked, each player loses half their life, rounded up.
Scourge of the Skyclaves's power and toughness are each equal to 20 minus the highest life total among players.

Sacred Foundry

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

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Mutagenic Growth

({G/P} can be paid with either {G} or 2 life.)
Target creature gets +2/+2 until end of turn.

Blood Crypt

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

Death's Shadow

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

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Bloodstained Mire

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