Here is the full list of all 79 Nioh: Complete Edition achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
You have unlocked all achievements!
Completed the 20th plane in The Abyss.
Equipped the Kusanagi Tsurugi, Yasakani Magatama, and Yata Mirror.
Equipped +15 divine equipment in all slots. (Excludes accessories.)
Made a total of 60 requests at the blacksmith.
Collected all the best materials.
Completed "The Grand Tournament" on Way of the Strong or higher.
Collected all Kodama from the Kyushu Region to the Omi Region.
Completed "The Master Ninja" on Way of the Strong or higher.
Bathed in every hot spring in the "Siege of Osaka (Summer)" chapter.
Completed 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Completed "The Last Samurai."
Collected all Guardian Spirits.
Defeated all types of yokai.
Destroyed all the Revenant contraptions on "The Last Samurai."
Collected all Kodama in the "Siege of Osaka (Summer)" chapter.
Completed "Resentment Unleashed."
Defeated the Onmoraki during "Resentment Unleashed."
Completed "The Sanada's Resolve."
Destroyed all the destructible cannons in "The Sanada's Resolve."
Completed "The Sparrow Flies Again."
Defeated Ganryu's Sasaki Kojiro using only Dual Wooden Swords. (Cannot use a Visitor/Companion.)
Changed the appearance of an item.
Completed "Scion of Virtue."
Collected all Kodama in the "Siege of Osaka (Winter)" chapter.
Defeated all of Sanada's Ten Braves in "Scion of Virtue."
Bathed in every hot spring in the "Siege of Osaka (Winter)" chapter.
Defeated Sarutobi Sasuke in the mission "The Siege of Osaka (Winter)" using only tonfa. (Cannot use a Visitor/Companion.)
Completed the mission "The Siege of Osaka (Winter)."
Used all the culverins in the mission "The Siege of Osaka (Winter)."
Listened to Katakura Shigenaga's entire introduction in "The One-Eyed Dragon's Castle."
Completed "Hands of the Dragon."
Completed "Spirit Stone Huntress."
Completed "The One-Eyed Dragon's Castle."
Collected all Kodama in the Tohoku region.
Bathed in every hot spring in the Tohoku region.
Seized all of Aoba Castle's three-storied keeps in "The One-Eyed Dragon's Castle."
Completed any mission while transformed into a woman.
Used a disguise.
Bathed in every hot spring from the Kyushu Region to the Omi Region.
Completed "Yokai Country."
Made two circuits around Japan.
Completed "The Queen's Eyes."
Defeated Derrick the Executioner.
Acquired mystic art for the tonfa.
Acquired mystic art for the dual swords.
Became Ryunoshin the dung lover's best friend.
Acquired 40 gestures.
Acquired mystic art for the sword.
Acquired mystic art for the axe.
Completed "The Demon King Revealed."
Obtained first divine item.
Used the mask of an ugly fellow to defeat an enemy.
Acquired mystic art for the kusarigama.
Completed "The Samurai from Sawayama."
Acquired mystic art for Ninjutsu.
Acquired mystic art for Onmyo Magic.
Completed "The Source of Evil."
Acquired mystic art for the spear.
Reached level 100.
Acquired mystic art for the odachi.
Witnessed Tokugawa's forces head toward a decisive battle.
Met with Tokugawa Ieyasu.
Found Muramasa and brought him in.
Communicated with a yokai 10 times.
Completed "The Demon of Mount Hiei."
Defeated the Nue of Mount Hiei.
Reached maximum proficiency with your first weapon.
Forged an item.
Collected all fragments of the Hiragumo teakettle from Shigisan.
Changed your hair style or beard.
Completed "The Ocean Roars Again."
Lit all three evil-warding bonfires in Itsukushima.
Completed your first Twilight mission.
Confused an enemy for the first time.
Completed "Deep in the Shadows."
Bathed in first hot spring.
Reached level 10.
Completed "The Man with the Guardian Spirit".