Tazri, Beacon of Unity

This spell costs {1} less to cast for each creature in your party.
{2/U}{2/B}{2/R}{2/G}: Look at the top six cards of your library. You may reveal up to two Cleric, Rogue, Warrior, Wizard, and/or Ally cards from among them and put them into your hand. Put the rest on the bottom of your library in a random order.

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.)

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.)

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.

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.)

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.

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.

Veteran Adventurer

Veteran Adventurer is also a Cleric, Rogue, Warrior, and Wizard.
This spell costs {1} less to cast for each creature in your party.
Vigilance

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}

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.

Tajuru Pathwarden

Vigilance (Attacking doesn't cause this creature to tap.)
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

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.)

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.

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.

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.)

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.)

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.

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.)

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.)

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.

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.

Thundering Sparkmage

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

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.