Sigil of Valor

Whenever equipped creature attacks alone, it gets +1/+1 until end of turn for each other creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Vanquisher's Banner

As Vanquisher's Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Upriser Renegade

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

Nezumi Ronin

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

Takeno, Samurai General

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)
Each other Samurai creature you control gets +1/+1 for each point of bushido it has.

Banishing Slash

Destroy up to one target artifact, enchantment, or tapped creature. Then if you control an artifact and an enchantment, create a 2/2 white Samurai creature token with vigilance.

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.

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.

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.

Risona, Asari Commander

Haste
Whenever Risona, Asari Commander deals combat damage to a player, if it doesn't have an indestructible counter on it, put an indestructible counter on it.
Whenever combat damage is dealt to you, remove an indestructible counter from Risona.

You Are Already Dead

Destroy target creature that was dealt damage this turn.
Draw a card.

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Godo, Bandit Warlord

When Godo, Bandit Warlord enters, you may search your library for an Equipment card, put it onto the battlefield, then shuffle.
Whenever Godo attacks for the first time each turn, untap it and all Samurai you control. After this phase, there is an additional combat phase.

Call to Glory

Untap all creatures you control. Samurai creatures you control get +1/+1 until end of 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.

Ironsoul Enforcer

Whenever Ironsoul Enforcer or a commander you control attacks alone, return target artifact card from your graveyard to the battlefield.

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.)

Invoke Despair

Target opponent sacrifices a creature. If they can't, they lose 2 life and you draw a card. Then repeat this process for an enchantment and a planeswalker.

Hand of Cruelty

Protection from white
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

Iizuka the Ruthless

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)
{2}{R}, Sacrifice a Samurai: Samurai creatures you control gain double strike until end of turn.

Tempered in Solitude

Whenever a creature you control attacks alone, exile the top card of your library. You may play that card this turn.

Kenzo the Hardhearted

Double strike; bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)

Bushi Tenderfoot

When a creature dealt damage by Bushi Tenderfoot this turn dies, flip Bushi Tenderfoot.

Bushi Tenderfoot // Kenzo the Hardhearted

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.)

Ancestral Katana

Whenever a Samurai or Warrior you control attacks alone, you may pay {1}. When you do, attach Ancestral Katana to it.
Equipped creature gets +2/+1.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Araba Mothrider

Flying
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

Sensei Golden-Tail

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
{1}{W}, {T}: Put a training counter on target creature. That creature gains bushido 1 and becomes a Samurai in addition to its other creature types. Activate only as a sorcery.

Michiko Konda, Truth Seeker

Whenever a source an opponent controls deals damage to you, that player sacrifices a permanent.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Angelic Exaltation

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of creatures you control.

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.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Konda's Banner

Konda's Banner can be attached only to a legendary creature.
Creatures that share a color with equipped creature get +1/+1.
Creatures that share a creature type with equipped creature get +1/+1.
Equip {2}

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Despark

Exile target permanent with mana value 4 or greater.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Invoke Justice

Return target permanent card from your graveyard to the battlefield, then distribute four +1/+1 counters among any number of creatures and/or Vehicles target player controls.

Eiganjo Exemplar

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

Imperial Oath

Create three 2/2 white Samurai creature tokens with vigilance. Scry 3.

Indebted Samurai

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever a Samurai you control dies, you may put a +1/+1 counter on Indebted Samurai.

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.

Vindicate

Akki Battle Squad

Whenever one or more modified creatures you control attack, untap all modified creatures you control. After this phase, there is an additional combat phase. This ability triggers only once each turn. (Equipment, Auras you control, and counters are modifications.)

Naomi, Pillar of Order

Whenever Naomi, Pillar of Order enters or attacks, if you control an artifact and an enchantment, create a 2/2 white Samurai creature token with vigilance.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Eiganjo Uprising

Create X 2/2 white Samurai creature tokens with vigilance. They gain menace and haste until end of turn.
Each opponent creates X minus one 2/2 white Samurai creature tokens with vigilance.

Mothrider Samurai

Nezumi Bladeblesser

Nezumi Bladeblesser has deathtouch as long as you control an artifact.
Nezumi Bladeblesser has menace as long as you control an enchantment. (It can't be blocked except by two or more creatures.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

The Wandering Emperor

Flash
As long as The Wandering Emperor entered this turn, you may activate her loyalty abilities any time you could cast an instant.
+1: Put a +1/+1 counter on up to one target creature. It gains first strike until end of turn.
−1: Create a 2/2 white Samurai creature token with vigilance.
−2: Exile target tapped creature. You gain 2 life.

Imperial Subduer

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

Konda, Lord of Eiganjo

Vigilance, indestructible
Bushido 5 (Whenever this creature blocks or becomes blocked, it gets +5/+5 until end of turn.)

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

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.

Nagao, Bound by Honor

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever Nagao, Bound by Honor attacks, Samurai creatures you control get +1/+1 until end of turn.

Tatsumasa, the Dragon's Fang

Equipped creature gets +5/+5.
{6}, Exile Tatsumasa, the Dragon's Fang: Create a 5/5 blue Dragon Spirit creature token with flying. Return Tatsumasa to the battlefield under its owner's control when that token dies.
Equip {3}

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Akki Ronin

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

Crackling Doom

Crackling Doom deals 2 damage to each opponent. Each opponent sacrifices a creature with the greatest power among creatures that player controls.

Sky-Blessed Samurai

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

Kentaro, the Smiling Cat

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
You may pay {X} rather than pay the mana cost for Samurai spells you cast, where X is that spell's mana value.

Hand of Honor

Protection from black
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

Arcane Signet

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

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.

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.