Legion Warboss

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token gains haste until end of turn and attacks this combat if able.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Trapjaw Tyrant

Enrage — Whenever this creature is dealt damage, exile target creature an opponent controls until this creature leaves the battlefield.

Mogg Maniac

Whenever this creature is dealt damage, it deals that much damage to target opponent or planeswalker.

Deafening Clarion

Choose one or both —
• Deafening Clarion deals 3 damage to each creature.
• Creatures you control gain lifelink until end of turn.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Plains

Inspiring Vantage

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

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Wall of Hope

Defender (This creature can't attack.)
Whenever this creature is dealt damage, you gain that much life.

Boros Reckoner

Whenever this creature is dealt damage, it deals that much damage to any target.
{R/W}: This creature gains first strike until end of turn.

Spiteful Sliver

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

Valorous Stance

Choose one —
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
• Destroy target creature with toughness 4 or greater.

Dauntless Bodyguard

As this creature enters, choose another creature you control.
Sacrifice this creature: The chosen creature gains indestructible until end of turn.

Boros Signet

Ajani Vengeant

+1: Target permanent doesn't untap during its controller's next untap step.
−2: Ajani deals 3 damage to any target and you gain 3 life.
−7: Destroy all lands target player controls.

Spinerock Knoll

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This land enters tapped.
{T}: Add {R}.
{R}, {T}: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.

Warrior en-Kor

{0}: The next 1 damage that would be dealt to this creature this turn is dealt to target creature you control instead.

Krenko, Tin Street Kingpin

Whenever Krenko attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Arcbond

Choose target creature. Whenever that creature is dealt damage this turn, it deals that much damage to each other creature and each player.

Shaman en-Kor

{0}: The next 1 damage that would be dealt to this creature this turn is dealt to target creature you control instead.
{1}{W}: The next time a source of your choice would deal damage to target creature this turn, that damage is dealt to this creature instead.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Shielded by Faith

Enchant creature
Enchanted creature has indestructible.
Whenever a creature enters, you may attach this Aura to that creature.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Mountain

Make a Stand

Creatures you control get +1/+0 and gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Outrider en-Kor

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{0}: The next 1 damage that would be dealt to this creature this turn is dealt to target creature you control instead.

Nomads en-Kor

Temple of Triumph

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {W}.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Gideon's Sacrifice

Choose a creature or planeswalker you control. All damage that would be dealt this turn to you and permanents you control is dealt to the chosen permanent instead (if it's still on the battlefield).

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Worn Powerstone

This artifact enters tapped.
{T}: Add {C}{C}.

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Command Tower

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

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Guilty Conscience

Enchant creature
Whenever enchanted creature deals damage, this Aura deals that much damage to that creature.

Coalhauler Swine

Whenever this creature is dealt damage, it deals that much damage to each player.

Stuffy Doll

Indestructible
As this creature enters, choose a player.
Whenever this creature is dealt damage, it deals that much damage to the chosen player.
{T}: This creature deals 1 damage to itself.

Spitemare

Whenever this creature is dealt damage, it deals that much damage to any target.

Truefire Captain

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever this creature is dealt damage, it deals that much damage to target player.