Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Blood Moon

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.

Back to Basics

Nonbasic lands don't untap during their controllers' untap steps.

Humility

All creatures lose all abilities and have base power and toughness 1/1.

Blind Obedience

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Artifacts and creatures your opponents control enter tapped.

Overburden

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

Mana Vortex

When you cast this spell, counter it unless you sacrifice a land.
At the beginning of each player's upkeep, that player sacrifices a land.
When there are no lands on the battlefield, sacrifice Mana Vortex.

Rising Waters

Lands don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player untaps a land they control.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Armageddon

Aura of Silence

Artifact and enchantment spells your opponents cast cost {2} more to cast.
Sacrifice Aura of Silence: Destroy target artifact or enchantment.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Decree of Silence

Whenever an opponent casts a spell, counter that spell and put a depletion counter on Decree of Silence. If there are three or more depletion counters on Decree of Silence, sacrifice it.
Cycling {4}{U}{U} ({4}{U}{U}, Discard this card: Draw a card.)
When you cycle Decree of Silence, you may counter target spell.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Solemnity

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

Mana Breach

Whenever a player casts a spell, that player returns a land they control to its owner's hand.