Here is the full list of all 31 9 Monkeys of Shaolin achievements.
Defeat Fudo.
Finish the game on Warrior difficulty.
Collect all weapons.
Defeat Okina.
Try every type of tea.
Defeat the Kasshiki.
Defeat Hannya.
Revive another player.
Defeat Shikami.
Gain more points than another player.
Learn first skill.
Complete a mission without taking any damage.
Complete a mission in co-op mode.
Destroy 30 items by throwing enemies into them.
Complete the prologue mission.
Master all styles.
Deflect projectiles 30 times.
Finish the game without dying.
The endless cycle of rebirth.
Kill an enemy in the air without touching the ground.
Parry 50 attacks.
Complete all missions.
Finish the game on Legend difficulty.
Collect all items.
Fully master the first style.
Fully master the second style.
Fully master the third style.
Kill 3 opponents with one strike.
Pull 5 enemies with one seal.
Kill 50 enemies using Qi energy.
Running from difficulties won't solve the problem.