All Will Be One

Whenever you put one or more counters on a permanent or player, All Will Be One deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Angelfire Ignition

Put two +1/+1 counters on target creature. It gains vigilance, trample, lifelink, indestructible, and haste until end of turn.
Flashback {2}{R}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Kalonian Hydra

Trample
Kalonian Hydra enters with four +1/+1 counters on it.
Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

Hopeful Initiate

Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)
{2}{W}, Remove two +1/+1 counters from among creatures you control: Destroy target artifact or enchantment.

Aragorn, Hornburg Hero

Attacking creatures you control have first strike and renown 1. (When a creature with renown 1 deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever a renowned creature you control deals combat damage to a player, double the number of +1/+1 counters on it.

Aragorn, Company Leader

Whenever the Ring tempts you, if you chose a creature other than Aragorn, Company Leader as your Ring-bearer, put your choice of a counter from among first strike, vigilance, deathtouch, and lifelink on Aragorn.
Whenever you put one or more counters on Aragorn, put one of each of those kinds of counters on up to one other target creature.

Consul's Lieutenant

First strike
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever Consul's Lieutenant attacks, if it's renowned, other attacking creatures you control get +1/+1 until end of turn.

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Biogenic Upgrade

Distribute three +1/+1 counters among one, two, or three target creatures, then double the number of +1/+1 counters on each of those creatures.

Drizzt Do'Urden

Double strike
When Drizzt Do'Urden enters, create Guenhwyvar, a legendary 4/1 green Cat creature token with trample.
Whenever a creature dies, if it had power greater than Drizzt's power, put a number of +1/+1 counters on Drizzt equal to the difference.

Aragorn and Arwen, Wed

Vigilance
Whenever Aragorn and Arwen, Wed enters or attacks, put a +1/+1 counter on each other creature you control. You gain 1 life for each other creature you control.

Temple Garden

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

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, Loyal Companion, that many plus one +1/+1 counters are put on it instead.

Duskshell Crawler

When Duskshell Crawler enters, put a +1/+1 counter on target creature.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Sacred Foundry

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

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Spectator Seating

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Command Tower

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

Alharu, Solemn Ritualist

When Alharu, Solemn Ritualist enters, put a +1/+1 counter on each of up to two other target creatures.
Whenever a nontoken creature you control with a +1/+1 counter on it dies, create a 1/1 white Spirit creature token with flying.
Partner (You can have two commanders if both have partner.)

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Valeron Wardens

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
Whenever a creature you control becomes renowned, draw a card.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Minsc & Boo, Timeless Heroes

When Minsc & Boo, Timeless Heroes enters and at the beginning of your upkeep, you may create Boo, a legendary 1/1 red Hamster creature token with trample and haste.
+1: Put three +1/+1 counters on up to one target creature with trample or haste.
−2: Sacrifice a creature. When you do, Minsc & Boo, Timeless Heroes deals X damage to any target, where X is that creature's power. If the sacrificed creature was a Hamster, draw X cards.
Minsc & Boo, Timeless Heroes can be your commander.

Bountiful Promenade

Bountiful Promenade enters tapped unless you have two or more opponents.
{T}: Add {G} or {W}.

Rishkar, Peema Renegade

When Rishkar, Peema Renegade enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Sunpetal Grove

Sunpetal Grove enters tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Bramblewood Paragon

Each other Warrior creature you control enters with an additional +1/+1 counter on it.
Each creature you control with a +1/+1 counter on it has trample.

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Outland Colossus

Renown 6 (When this creature deals combat damage to a player, if it isn't renowned, put six +1/+1 counters on it and it becomes renowned.)
Outland Colossus can't be blocked by more than one creature.

Verdurous Gearhulk

Trample
When Verdurous Gearhulk enters, distribute four +1/+1 counters among any number of target creatures you control.