Here is the full list of all 42 Labyrinth of Zangetsu achievements.
Earn all trophies
Overcome the Blightbane Trial
Defeat the Yatsutsuki Spider in Sanroku Jukai Forest
Defeat the Moondrinker Dragon in the Ancient Pyroducts
Defeat the A-Un in Kurehasu Temple Gardens
Defeat the Saint of the Blessed Moon in Kurehasu's Finger
Defeat Oborogami
Defeat 100 Undead
Defeat 100 Insects
Defeat 100 Yokai
Defeat 100 Oni
Defeat 100 Dragons
Reach 1,000 total kills
Reach 5,000 total kills
Reach 15,000 total kills
Reach Warrior Master Level (Lv. 20)
Reach Thief Master Level (Lv. 20)
Reach Cleric Master Level (Lv. 20)
Reach Wizard Master Level (Lv. 20)
Reach Samurai Master Level (Lv. 20)
Reach Monk Master Level (Lv. 20)
Reach Paladin Master Level (Lv. 20)
Reach Ninja Master Level (Lv. 20)
Reach Sage Master Level (Lv. 30)
Play for a total of 10 hours
Play for a total of 50 hours
Play for a total of 100 hours
Obtain 30 different items in labyrinths
Obtain 80 different items in labyrinths
Obtain 140 different items in labyrinths
Collect 10,000 sen
Collect 100,000 sen
Collect 1,000,000 sen
Master 3 classes on the same character
Master 6 classes on the same character
Master 9 classes on the same character
Defeat the tengu in the Jukai Forest
Jump into the lava in the Ancient Pyroducts
Defeat the Gashadokuro in Kurehasu's Finger
Defeat the Black Maneki-Neko in Mt. Fugaku Cauldron
Recover the corpses of a party killed within a Labyrinth
Lose a character at class level 20 or higher