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