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.

Reflection of Kiki-Jiki

{1}, {T}: Create a token that's a copy of another target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Fable of the Mirror-Breaker

(As this Saga enters and after your draw step, add a lore counter.)
I — Create a 2/2 red Goblin Shaman creature token with "Whenever this token attacks, create a Treasure token."
II — You may discard up to two cards. If you do, draw that many cards.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Fable of the Mirror-Breaker // Reflection of Kiki-Jiki

Ancestral Katana

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

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.

Plains

Twinshot Sniper

Reach
When this creature enters, it deals 2 damage to any target.
Channel — {1}{R}, Discard this card: It deals 2 damage to any target.

Experimental Synthesizer

When this artifact enters or leaves the battlefield, exile the top card of your library. Until end of turn, you may play that card.
{2}{R}, Sacrifice this artifact: Create a 2/2 white Samurai creature token with vigilance. Activate only as a sorcery.

Eater of Virtue

Whenever equipped creature dies, exile it.
Equipped creature gets +2/+0.
As long as a card exiled with Eater of Virtue has flying, equipped creature has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, protection, reach, trample, and vigilance.
Equip {1}

Imperial Subduer

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

Akki Ronin

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

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.

Mountain

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.

Tempered in Solitude

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

Spirited Companion

Ninja's Kunai

Equipped creature has "{1}, {T}, Sacrifice Ninja's Kunai: Ninja's Kunai deals 3 damage to any target."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Eiganjo Exemplar

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

Selfless Samurai

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