Bazaar of Wonders

When this enchantment enters, exile all graveyards.
Whenever a player casts a spell, counter it if a card with the same name is in a graveyard or a nontoken permanent with the same name is on the battlefield.

Ishai, Ojutai Dragonspeaker

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Ishai.
Partner (You can have two commanders if both have partner.)

Bile Blight

Target creature and all other creatures with the same name as that creature get -3/-3 until end of turn.

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)

Cornered Market

Players can't cast spells with the same name as a nontoken permanent.
Players can't play nonbasic lands with the same name as a nontoken permanent.

Spy Kit

Equipped creature gets +1/+1 and has all names of nonlegendary creature cards in addition to its name.
Equip {2}

Evil Twin

You may have this creature enter as a copy of any creature on the battlefield, except it has "{U}{B}, {T}: Destroy target creature with the same name as this creature."

Bifurcate

Search your library for a permanent card with the same name as target nontoken creature, put that card onto the battlefield, then shuffle.

Detention Sphere

When this enchantment enters, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.
When this enchantment leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

Echoing Decay

Target creature and all other creatures with the same name as that creature get -2/-2 until end of turn.

Echoing Courage

Target creature and all other creatures with the same name as that creature get +2/+2 until end of turn.