Mountain

Boros Fury-Shield

Prevent all combat damage that would be dealt by target attacking or blocking creature this turn. If {R} was spent to cast this spell, Boros Fury-Shield deals damage to that creature's controller equal to the creature's power.

Firemane Avenger

Flying
Battalion — Whenever this creature and at least two other creatures attack, this creature deals 3 damage to any target and you gain 3 life.

Hellraiser Goblin

Creatures you control have haste and attack each combat if able.

Justice Strike

Target creature deals damage to itself equal to its power.

Plains

Aurelia, Exemplar of Justice

Flying
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, choose up to one target creature you control. Until end of turn, that creature gets +2/+0, gains trample if it's red, and gains vigilance if it's white.

Sunhome Stalwart

First strike (This creature deals combat damage before creatures without first strike.)
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Viashino Firstblade

Haste
When this creature enters, it gets +2/+2 until end of turn.

Goblin Banneret

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
{1}{R}: This creature gets +2/+0 until end of turn.

Concealed Weapon

Equipped creature gets +3/+0.
Disguise {2}{R} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this Equipment is turned face up, attach it to target creature you control.
Equip {1}{R}

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.

Chance for Glory

Creatures you control gain indestructible. Take an extra turn after this one. At the beginning of that turn's end step, you lose the game.

Boros Swiftblade

Swiftblade Vindicator

Double strike (This creature deals both first-strike and regular combat damage.)
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.)

Frontline Medic

Battalion — Whenever this creature and at least two other creatures attack, creatures you control gain indestructible until end of turn.
Sacrifice this creature: Counter target spell with {X} in its mana cost unless its controller pays {3}.

Boros Elite

Battalion — Whenever this creature and at least two other creatures attack, this creature gets +2/+2 until end of turn.

Skyknight Legionnaire

Boros Guildmage

{1}{R}: Target creature gains haste until end of turn.
{1}{W}: Target creature gains first strike until end of turn.

Boros Recruit

({R/W} can be paid with either {R} or {W}.)
First strike

Resurgence

Creatures you control gain first strike and vigilance until end of turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Response

Response deals 5 damage to target attacking or blocking creature.

Response // Resurgence

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Ordruun Mentor

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever you attack a player, target creature that's attacking that player gains first strike until end of turn.

Legion Loyalist

Haste
Battalion — Whenever this creature and at least two other creatures attack, creatures you control gain first strike and trample until end of turn and can't be blocked by creature tokens this turn.

Boros Challenger

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
{2}{R}{W}: This creature gets +1/+1 until end of turn.

Firefist Striker

Battalion — Whenever this creature and at least two other creatures attack, target creature can't block this turn.

Skyknight Vanguard

Flying
Whenever this creature attacks, create a 1/1 white Soldier creature token that's tapped and attacking.

Aegis of the Legion

Equipped creature gets +1/+1 and has mentor. (Whenever it attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever equipped creature mentors a creature, put a shield counter on that creature. (If that creature would be dealt damage or destroyed, remove a shield counter from it instead.)
Equip {3}

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.

Bathe in Light

Radiance — Choose a color. Target creature and each other creature that shares a color with it gain protection from the chosen color until end of turn.