Black Mage's Rod

Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.)
Equipped creature gets +1/+0, has "Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent," and is a Wizard in addition to its other types.
Equip {3}

Drana's Silencer

When this creature enters, target creature an opponent controls gets -X/-X until end of turn, where X is the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Deadly Alliance

This spell costs {1} less to cast for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
Destroy target creature or planeswalker.

Concerted Defense

Counter target noncreature spell unless its controller pays {1} plus an additional {1} for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Cid, Freeflier Pilot

Equipment and Vehicle spells you cast cost {1} less to cast.
Jump — During your turn, Cid has flying.
{2}, {T}: Return target Equipment or Vehicle card from your graveyard to your hand.

Blue Mage's Cane

Job select
Equipped creature gets +0/+2, is a Wizard in addition to its other types, and has "Whenever this creature attacks, exile up to one target instant or sorcery card from defending player's graveyard. If you do, copy it. You may cast the copy by paying {3} rather than paying its mana cost."
Spirit of the Whalaqee — Equip {2}

Plains

Thwart the Grave

This spell costs {1} less to cast for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
Return target creature card and up to one target Cleric, Rogue, Warrior, or Wizard creature card from your graveyard to the battlefield.

Allied Assault

Up to two target creatures each get +X/+X until end of turn, where X is the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Emeria Captain

Flying, vigilance
When this creature enters, put a +1/+1 counter on it for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Thief's Knife

Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.)
Equipped creature gets +1/+1, has "Whenever this creature deals combat damage to a player, draw a card," and is a Rogue in addition to its other types.
Equip {4}

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.)

Sage's Nouliths

Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.)
Equipped creature gets +1/+0, has "Whenever this creature attacks, untap target attacking creature," and is a Cleric in addition to its other types.
Hagneia — Equip {3}

Sol Ring

White Mage's Staff

Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.)
Equipped creature gets +1/+1, has "Whenever this creature attacks, you gain 1 life," and is a Cleric in addition to its other types.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Skyclave Plunder

Look at the top X cards of your library, where X is three plus the number of creatures in your party. Put three of those cards into your hand and the rest on the bottom of your library in a random order. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Linvala, Shield of Sea Gate

Flying
At the beginning of combat on your turn, if you have a full party, choose target nonland permanent an opponent controls. Until your next turn, it can't attack or block, and its activated abilities can't be activated.
Sacrifice Linvala: Choose hexproof or indestructible. Creatures you control gain that ability until end of turn.

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.

Sea Gate Colossus

This spell costs {1} less to cast for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Seafloor Stalker

{4}{U}: This creature gets +1/+0 until end of turn and can't be blocked this turn. This ability costs {1} less to activate for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Stick Together

Each player chooses a party from among creatures they control, then sacrifices the rest. (To choose a party, choose up to one each of Cleric, Rogue, Warrior, and Wizard.)

Archpriest of Iona

Archpriest of Iona's power is equal to the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
At the beginning of combat on your turn, if you have a full party, target creature gets +1/+1 and gains flying until end of turn.

Arcane Signet

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

Spoils of Adventure

This spell costs {1} less to cast for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
You gain 3 life and draw three cards.

Nalia de'Arnise

You may look at the top card of your library any time.
You may cast Cleric, Rogue, Warrior, and Wizard spells from the top of your library.
At the beginning of combat on your turn, if you have a full party, put a +1/+1 counter on each creature you control and those creatures gain deathtouch until end of turn.

Shepherd of Heroes

Flying
When this creature enters, you gain 2 life for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

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.

Journey to Oblivion

This spell costs {1} less to cast for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

Coveted Prize

This spell costs {1} less to cast for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
Search your library for a card, put it into your hand, then shuffle. If you have a full party, you may cast a spell with mana value 4 or less from your hand without paying its mana cost.

Squad Commander

When this creature enters, create a 1/1 white Kor Warrior creature token for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)
At the beginning of combat on your turn, if you have a full party, creatures you control get +1/+0 and gain indestructible until end of turn.

Astrologian's Planisphere

Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.)
Equipped creature is a Wizard in addition to its other types and has "Whenever you cast a noncreature spell and whenever you draw your third card each turn, put a +1/+1 counter on this creature."
Diana — Equip {2}

Cascade Seer

When this creature enters, scry X, where X is the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Nimble Trapfinder

This creature can't be blocked if you had another Cleric, Rogue, Warrior, or Wizard enter the battlefield under your control this turn.
At the beginning of combat on your turn, if you have a full party, creatures you control gain "Whenever this creature deals combat damage to a player, draw a card" until end of turn.

Swamp

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.

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}

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.

Kabira Outrider

When this creature enters, target creature gets +1/+1 until end of turn for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Acquisitions Expert

When this creature enters, target opponent reveals a number of cards from their hand equal to the number of creatures in your party. You choose one of those cards. That player discards that card. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Island

Practiced Tactics

Choose target attacking or blocking creature. Practiced Tactics deals damage to that creature equal to twice the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Command Tower

Malakir Blood-Priest

When this creature enters, each opponent loses X life and you gain X life, where X is the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)