Ronin Houndmaster

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

Upriser Renegade

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

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.

Gilgamesh, Master-at-Arms

Whenever Gilgamesh enters or attacks, look at the top six cards of your library. You may put any number of Equipment cards from among them onto the battlefield. Put the rest on the bottom of your library in a random order. When you put one or more Equipment onto the battlefield this way, you may attach one of them to a Samurai you control.

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.)

Akki Ronin

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

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.

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.)

Fumiko the Lowblood

Fumiko has bushido X, where X is the number of attacking creatures. (Whenever this creature blocks or becomes blocked, it gets +X/+X until end of turn.)
Creatures your opponents control attack each combat if able.

Battle-Mad Ronin

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)
This creature attacks each combat if able.

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.

Sokenzan Spellblade

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
{1}{R}: This creature gets +X/+0 until end of turn, where X is the number of cards in your hand.

Ronin Cliffrider

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever this creature attacks, you may have it deal 1 damage to each creature defending player controls.

Nameless Conqueror

The Shattered States Era

(As this Saga enters and after your draw step, add a lore counter.)
I — Gain control of target creature until end of turn. Untap it. It gains haste until end of turn.
II — Creatures you control get +1/+0 until end of turn.
III — Exile this Saga, then return it to the battlefield transformed under your control.