Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Arcane Signet

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

Propaganda

Pattern Matcher

When Pattern Matcher enters, you may search your library for a card with the same name as another creature you control, reveal it, put it into your hand, then shuffle.

Azorius Signet

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.

Remembrance

Whenever a nontoken creature you control dies, you may search your library for a card with the same name as that creature, reveal it, put it into your hand, then shuffle.

Locket of Yesterdays

Spells you cast cost {1} less to cast for each card with the same name as that spell in your graveyard.

Mechanized Production

Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.

Chrome Replicator

When Chrome Replicator enters, if you control two or more nonland, nontoken permanents with the same name as one another, create a 4/4 colorless Construct artifact creature token.

Thorn of Amethyst

Noncreature spells cost {1} more to cast.

Retraced Image

Reveal a card in your hand, then put that card onto the battlefield if it has the same name as a permanent.

Winter Orb

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Plains

Aven Shrine

Whenever a player casts a spell, that player gains X life, where X is the number of cards in all graveyards with the same name as that spell.

Island

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Static Orb

As long as Static Orb is untapped, players can't untap more than two permanents during their untap steps.

Sol Ring

Assembly Hall

{4}, {T}: Reveal a creature card in your hand. Search your library for a card with the same name as that card, reveal it, put it into your hand, then shuffle.

Mask of the Mimic

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card with the same name as target nontoken creature, put that card onto the battlefield, then shuffle.