Izzet Signet

Sol Ring

Knotvine Paladin

Whenever Knotvine Paladin attacks, it gets +1/+1 until end of turn for each untapped creature you control.

Plains

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Gruul Signet

Azorius Signet

Simic Signet

Golgari Signet

Have

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Boros Signet

Arcane Signet

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

Grand Abolisher

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.

Cold-Eyed Selkie

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Cold-Eyed Selkie deals combat damage to a player, you may draw that many cards.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Selesnya Signet

Orzhov Signet

Forest

Dimir Signet

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Rakdos Signet

Island

Getting

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Rafiq of the Many

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, it gains double strike until end of turn.