The Council of Four

Whenever a player draws their second card during their turn, you draw a card.
Whenever a player casts their second spell during their turn, you create a 2/2 white Knight creature token.

Marisi, Breaker of the Coil

Your opponents can't cast spells during combat.
Whenever a creature you control deals combat damage to a player, goad each creature that player controls. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Bruse Tarl, Boorish Herder

Whenever Bruse Tarl enters or attacks, target creature you control gains double strike and lifelink until end of turn.
Partner (You can have two commanders if both have partner.)

Akroan Conscriptor

Heroic — Whenever you cast a spell that targets this creature, gain control of another target creature until end of turn. Untap that creature. It gains haste until end of turn.

Gor Muldrak, Amphinologist

You and permanents you control have protection from Salamanders.
At the beginning of your end step, each player who controls the fewest creatures creates a 4/3 blue Salamander Warrior creature token.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Arcane Signet

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

Have

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Manalith

Boromir, Warden of the Tower

Vigilance
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
Sacrifice Boromir: Creatures you control gain indestructible until end of turn. The Ring tempts you.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Command Tower

True Conviction

Creatures you control have double strike and lifelink.

Thrasios, Triton Hero

{4}: Scry 1, then reveal the top card of your library. If it's a land card, put it onto the battlefield tapped. Otherwise, draw a card.
Partner (You can have two commanders if both have partner.)

Aesi, Tyrant of Gyre Strait

You may play an additional land on each of your turns.
Landfall — Whenever a land you control enters, you may draw a card.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Kynaios and Tiro of Meletis

At the beginning of your end step, draw a card. Each player may put a land card from their hand onto the battlefield, then each opponent who didn't draws a card.

Relic of Legends

{T}: Add one mana of any color.
Tap an untapped legendary creature you control: Add one mana of any color.

Sol Ring

Savor the Moment

Take an extra turn after this one. Skip the untap step of that turn.

Coalition Relic

{T}: Add one mana of any color.
{T}: Put a charge counter on this artifact.
At the beginning of your first main phase, remove all charge counters from this artifact. Add one mana of any color for each charge counter removed this way.

Swords to Plowshares

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

Aragorn, the Uniter

Whenever you cast a white spell, create a 1/1 white Human Soldier creature token.
Whenever you cast a blue spell, scry 2.
Whenever you cast a red spell, Aragorn deals 3 damage to target opponent.
Whenever you cast a green spell, target creature gets +4/+4 until end of turn.