Reinforced Ronin

Haste
At the beginning of your end step, return Reinforced Ronin to its owner's hand.
Channel — {1}{R}, Discard Reinforced Ronin: Draw a card.

Eiganjo Exemplar

Whenever a Samurai or Warrior you control attacks alone, it gets +1/+1 until end of turn.

Lizard Blades

Double strike
Equipped creature has double strike.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Paragon of Fierce Defiance

Other red creatures you control get +1/+1.
{R}, {T}: Another target red creature you control gains haste until end of turn. (It can attack and {T} this turn.)

Bladegraft Aspirant

Menace
Equipment spells you cast cost {1} less to cast.
Activated abilities of Equipment you control that target Bladegraft Aspirant cost {1} less to activate.

Martial Glory

Target creature gets +3/+0 until end of turn.
Target creature gets +0/+3 until end of turn.

Sunblade Samurai

Vigilance
Channel — {2}, Discard Sunblade Samurai: Search your library for a basic Plains card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Tiamat's Fanatics

Haste
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Raiyuu, Storm's Edge

First strike
Whenever a Samurai or Warrior you control attacks alone, untap it. If it's the first combat phase of the turn, there is an additional combat phase after this phase.

Wrecking Crew

Ogre-Head Helm

Equipped creature gets +2/+2.
Whenever Ogre-Head Helm or equipped creature deals combat damage to a player, you may sacrifice it. If you do, discard your hand, then draw three cards.
Reconfigure {3} ({3}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Krenko's Enforcer

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Oreskos Swiftclaw

Heiko Yamazaki, the General

Trample
Whenever a Samurai or Warrior you control attacks alone, you may cast target artifact card from your graveyard this turn.

Frenzied Saddlebrute

Haste
All creatures can attack your opponents and planeswalkers your opponents control as though those creatures had haste.

Pugnacious Pugilist

Whenever Pugnacious Pugilist attacks, create a tapped and attacking 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."
Blitz {3}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Icewind Stalwart

Protection Fighting Style — When Icewind Stalwart enters the battlefield, exile up to one target non-Warrior creature you control, then return it to the battlefield under its owner's control.

Skophos Reaver

As long as it's your turn, Skophos Reaver gets +2/+0.
Madness {1}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Mogg War Marshal

Echo {1}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Mogg War Marshal enters the battlefield or dies, create a 1/1 red Goblin creature token.

Unstoppable Ogre

When Unstoppable Ogre enters the battlefield, target creature can't block this turn.

Norika Yamazaki, the Poet

Vigilance
Whenever a Samurai or Warrior you control attacks alone, you may cast target enchantment card from your graveyard this turn.

Asari Captain

Haste
Whenever a Samurai or Warrior you control attacks alone, it gets +1/+0 until end of turn for each Samurai or Warrior you control.

Kruin Striker

Whenever another creature enters the battlefield under your control, Kruin Striker gets +1/+0 and gains trample until end of turn.

Rabbit Battery

Haste
Equipped creature gets +1/+1 and has haste.
Reconfigure {R} ({R}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Akki Ronin

Whenever a Samurai or Warrior you control attacks alone, you may discard a card. If you do, draw a card.

Goro-Goro, Disciple of Ryusei

{R}: Creatures you control gain haste until end of turn.
{3}{R}{R}: Create a 5/5 red Dragon Spirit creature token with flying. Activate only if you control an attacking modified creature. (Equipment, Auras you control, and counters are modifications.)

Seven-Tail Mentor

When Seven-Tail Mentor enters the battlefield or dies, put a +1/+1 counter on target creature or Vehicle you control.

Devilish Valet

Trample, haste
Alliance — Whenever another creature enters the battlefield under your control, double Devilish Valet's power until end of turn.

Borderland Marauder

Whenever Borderland Marauder attacks, it gets +2/+0 until end of turn.

Jaxis, the Troublemaker

{R}, {T}, Discard a card: Create a token that's a copy of another target creature you control. It gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step. Activate only as a sorcery.
Blitz {1}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Sky-Blessed Samurai

This spell costs {1} less to cast for each enchantment you control.
Flying

Foundry Helix

As an additional cost to cast this spell, sacrifice a permanent.
Foundry Helix deals 4 damage to any target. If the sacrificed permanent was an artifact, you gain 4 life.

Upriser Renegade

Upriser Renegade gets +2/+0 for each other modified creature you control. (Equipment, Auras you control, and counters are modifications.)

Imperial Subduer

Whenever a Samurai or Warrior you control attacks alone, tap target creature you don't control.

Goblin Javelineer

Haste
Whenever Goblin Javelineer becomes blocked, it deals 1 damage to target creature blocking it.

Selfless Samurai

Whenever a Samurai or Warrior you control attacks alone, it gains lifelink until end of turn.
Sacrifice Selfless Samurai: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Champion of the Flame

Trample
Champion of the Flame gets +2/+2 for each Aura and Equipment attached to it.

Foundry Street Denizen

Whenever another red creature enters the battlefield under your control, Foundry Street Denizen gets +1/+0 until end of turn.

Swashbuckler Extraordinaire

When Swashbuckler Extraordinaire enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you attack, you may sacrifice one or more Treasures. When you do, up to that many target creatures gain double strike until end of turn.

Chimney Rabble

Haste
When Chimney Rabble enters the battlefield, create a 1/1 red Phyrexian Goblin creature token.

Ballroom Brawlers

Whenever Ballroom Brawlers attacks, Ballroom Brawlers and up to one other target creature you control both gain your choice of first strike or lifelink until end of turn.

Peerless Samurai

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a Samurai or Warrior you control attacks alone, the next spell you cast this turn costs {1} less to cast.

Seeker of the Way

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, Seeker of the Way gains lifelink until end of turn.

Ondu Champion

Rally — Whenever Ondu Champion or another Ally enters the battlefield under your control, creatures you control gain trample until end of turn.

Spear Spewer

Defender
{T}: Spear Spewer deals 1 damage to each player.

Stingscourger

Echo {3}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Stingscourger enters the battlefield, return target creature an opponent controls to its owner's hand.

Mayhem Patrol

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Mayhem Patrol attacks, target creature gets +1/+0 until end of turn.
Blitz {1}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Furnace Punisher

Menace
At the beginning of each player's upkeep, Furnace Punisher deals 2 damage to that player unless they control two or more basic lands.

Scrapyard Steelbreaker

{1}, Sacrifice another artifact: Scrapyard Steelbreaker gets +2/+1 until end of turn.

Mage-Ring Bully

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Mage-Ring Bully attacks each combat if able.

Akki Ember-Keeper

Whenever a nontoken modified creature you control dies, create a 1/1 colorless Spirit creature token. (Equipment, Auras you control, and counters are modifications.)

Lavastep Raider

{2}{R}: Lavastep Raider gets +2/+0 until end of turn.

Plasma Jockey

Whenever Plasma Jockey attacks, target creature an opponent controls can't block this turn.
Blitz {2}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)