Heir of the Ancient Fang

Heir of the Ancient Fang enters with a +1/+1 counter on it if you control a modified creature. (Equipment, Auras you control, and counters are modifications.)

Jukai Trainee

Whenever Jukai Trainee blocks or becomes blocked, it gets +1/+1 until end of turn.

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.)

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.

Ronin Houndmaster

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

Accorder's Shield

Equipped creature gets +0/+3 and has vigilance. (Attacking doesn't cause it to tap.)
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Jade Avenger

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

Battle-Mad Ronin

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

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.

The Shattered States Era // Nameless Conqueror

Chishiro, the Shattered Blade

Whenever an Aura or Equipment you control enters, create a 2/2 red Spirit creature token with menace.
At the beginning of your end step, put a +1/+1 counter on each modified creature you control. (Equipment, Auras you control, and counters are modifications.)

Ronin Cliffrider

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

Upriser Renegade

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

Fumiko the Lowblood

Fumiko the Lowblood 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.

Isao, Enlightened Bushi

This spell can't be countered.
Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)
{2}: Regenerate target Samurai.

Aether Sting

Whenever an opponent casts a creature spell, Aether Sting deals 1 damage to that player.

Adventuring Gear

Landfall — Whenever a land you control enters, equipped creature gets +2/+2 until end of turn.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Akki Ronin

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

Kosei, Penitent Warlord

As long as Kosei, Penitent Warlord is enchanted, equipped, and has a counter on it, Kosei has "Whenever Kosei, Penitent Warlord deals combat damage to an opponent, you draw that many cards and Kosei deals that much damage to each other opponent."

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.