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.

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.

Akki Ronin

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

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.)

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Eiganjo Exemplar

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

Mountain

Bruenor Battlehammer

Each creature you control gets +2/+0 for each Equipment attached to it.
You may pay {0} rather than pay the equip cost of the first equip ability you activate each turn.

Cloudsteel Kirin

Flying
Equipped creature has flying and "You can't lose the game and your opponents can't win the game."
Reconfigure {5} ({5}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Boros Guildgate

Boros Guildgate enters tapped.
{T}: Add {R} or {W}.

Imperial Subduer

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

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.

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.)

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.)

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.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

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.

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.

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.)

Boros Locket

{T}: Add {R} or {W}.
{R/W}{R/W}{R/W}{R/W}, {T}, Sacrifice Boros Locket: Draw two cards.

Boros Keyrune

{T}: Add {R} or {W}.
{R}{W}: Boros Keyrune becomes a 1/1 red and white Soldier artifact creature with double strike until end of turn. (It deals both first-strike and regular combat damage.)

Tempered in Solitude

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

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

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.

Plains

Upriser Renegade

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

Boros Signet

Seven-Tail Mentor

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

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.

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.

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.