Akki Ronin

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

Have

Mothrider Samurai

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

Imperial Subduer

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

Silverstorm Samurai

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

Devoted Retainer

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

Eiganjo Exemplar

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

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.)

Imperial Oath

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

Plains

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.

Swamp

Mountain

Seven-Tail Mentor

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

Network Terminal

{T}: Add one mana of any color.
{1}, {T}, Tap another untapped artifact you control: Draw a card, then discard a card.

Takeno's Cavalry

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
{T}: Takeno's Cavalry deals 1 damage to target attacking or blocking Spirit.

Cursed Ronin

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
{B}: Cursed Ronin gets +1/+1 until end of turn.

Call to Glory

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