Ashes of the Abhorrent

Players can't cast spells from graveyards or activate abilities of cards in graveyards.
Whenever a creature dies, you gain 1 life.

Path of Bravery

As long as your life total is greater than or equal to your starting life total, creatures you control get +1/+1.
Whenever one or more creatures you control attack, you gain life equal to the number of attacking creatures.

Righteous Cause

Whenever a creature attacks, you gain 1 life.

Oblivion Ring

When Oblivion Ring enters, exile another target nonland permanent.
When Oblivion Ring leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Seal of Cleansing

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

Oubliette

When Oubliette enters, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Stasis

Players skip their untap steps.
At the beginning of your upkeep, sacrifice Stasis unless you pay {U}.

Overburden

Whenever a player puts a nontoken creature onto the battlefield, that player returns a land they control to its owner's hand.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Conclave Tribunal

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
When Conclave Tribunal enters, exile target nonland permanent an opponent controls until Conclave Tribunal leaves the battlefield.

Solemnity

Players can't get counters.
Counters can't be put on artifacts, creatures, enchantments, or lands.

Netherese Puzzle-Ward

Focus Beam — At the beginning of your upkeep, roll a d4. Scry X, where X is the result.
Perfect Illumination — Whenever you roll a die's highest natural result, draw a card.

Grave Betrayal

Whenever a creature you don't control dies, return it to the battlefield under your control with an additional +1/+1 counter on it at the beginning of the next end step. That creature is a black Zombie in addition to its other colors and types.

Cast Out

Flash
When Cast Out enters, exile target nonland permanent an opponent controls until Cast Out leaves the battlefield.
Cycling {W} ({W}, Discard this card: Draw a card.)

Martial Law

At the beginning of your upkeep, detain target creature an opponent controls. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

Ixalan's Binding

When Ixalan's Binding enters, exile target nonland permanent an opponent controls until Ixalan's Binding leaves the battlefield.
Your opponents can't cast spells with the same name as the exiled card.

Confounding Conundrum

When Confounding Conundrum enters, draw a card.
Whenever a land enters under an opponent's control, if that player had another land enter the battlefield under their control this turn, they return a land they control to its owner's hand.