Swamp

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Choked Estuary

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.

Shattered Sanctum

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

Arcane Signet

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

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

The Destined Thief

The Destined Thief can't be blocked.
{U}, {T}: Another target creature you control can't be blocked this turn.
Whenever one or more creatures you control deal combat damage to one or more players, draw a card, then discard a card. If you have a full party, instead draw three cards.

Isolated Chapel

This land enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Chaos Shrine's Black Crystal

Whenever a nontoken creature you control dies, exile it.
At the beginning of your upkeep, you may put a creature card exiled with Chaos Shrine's Black Crystal onto the battlefield under your control with a finality counter on it.

The Destined Warrior

First strike, vigilance, menace
Cleric, Rogue, Warrior, and Wizard spells you cast cost {1} less to cast.
At the beginning of combat on your turn, creatures you control get +1/+0 until end of turn. If you have a full party, creatures you control get +3/+0 until end of turn instead.

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Burakos, Party Leader

Burakos is also a Cleric, Rogue, Warrior, and Wizard.
Whenever Burakos attacks, defending player loses X life and you create X Treasure tokens, where X is the number of creatures in your party.
Choose a Background (You can have a Background as a second commander.)

Watery Grave

({T}: Add {U} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Morphic Pool

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

The Destined White Mage

Lifelink
{W}, {T}: Another target creature you control gains lifelink until end of turn.
Whenever you gain life, put a +1/+1 counter on target creature you control. If you have a full party, put three +1/+1 counters on that creature instead.

Port Town

As this land enters, you may reveal a Plains or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {W} or {U}.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Plains

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Azorius Signet

Island

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Dimir Signet

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. This artifact deals 1 damage to you.

Sol Ring

Vault of Champions

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Deserted Beach

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

Orzhov Signet

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Multiclass Baldric

Equipped creature has lifelink if you control a Cleric, deathtouch if you control a Rogue, haste if you control a Warrior, and flying if you control a Wizard.
As long as you have a full party, prevent all damage that would be dealt to equipped creature.
Equip {2}

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Shipwreck Marsh

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

Prairie Stream

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

Godless Shrine

({T}: Add {W} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

The Destined Black Mage

Deathtouch
{B}, {T}: Another target creature you control gains deathtouch until end of turn.
Whenever you cast a noncreature spell, The Destined Black Mage deals 1 damage to each opponent. If you have a full party, it deals 3 damage to each opponent instead.

Command Tower

Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.