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 Master Ninja" on Way of the Strong or higher.
Completed "The Grand Tournament" on Way of the Strong or higher.
Collected all Kodama in the "Siege of Osaka (Summer)" chapter.
Completed "The Last Samurai."
Collected all Guardian Spirits.
Defeated all types of yokai.
Destroyed all the Revenant contraptions on "The Last Samurai."
Bathed in every hot spring 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."
Defeated Ganryu's Sasaki Kojiro using only Dual Wooden Swords. (Cannot use a Visitor/Companion.)
Completed "The Sparrow Flies Again."
Completed "Scion of Virtue."
Bathed in every hot spring in the "Siege of Osaka (Winter)" chapter.
Collected all Kodama in the "Siege of Osaka (Winter)" chapter.
Defeated all of Sanada's Ten Braves in "Scion of Virtue."
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)."
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.
Listened to Katakura Shigenaga's entire introduction in "The One-Eyed Dragon's Castle."
Seized all of Aoba Castle's three-storied keeps in "The One-Eyed Dragon's Castle."
Completed "Yokai Country."
Collected all Kodama from the Kyushu Region to the Omi Region.
Bathed in every hot spring from the Kyushu Region to the Omi Region.
Communicated with a yokai 10 times.
Made two circuits around Japan.
Completed "The Queen's Eyes."
Defeated Derrick the Executioner.
Became Ryunoshin the dung lover's best friend.
Acquired mystic art for the tonfa.
Acquired mystic art for the axe.
Completed "The Demon King Revealed."
Obtained first divine item.
Completed "The Samurai from Sawayama."
Completed any mission while transformed into a woman.
Used a disguise.
Acquired 40 gestures.
Acquired mystic art for the odachi.
Acquired mystic art for Ninjutsu.
Acquired mystic art for the kusarigama.
Completed 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Acquired mystic art for Onmyo Magic.
Reached level 100.
Acquired mystic art for the dual swords.
Completed "The Source of Evil."
Collected all fragments of the Hiragumo teakettle from Shigisan.
Acquired mystic art for the sword.
Acquired mystic art for the spear.
Witnessed Tokugawa's forces head toward a decisive battle.
Met with Tokugawa Ieyasu.
Found Muramasa and brought him in.
Reached maximum proficiency with your first weapon.
Completed "The Demon of Mount Hiei."
Defeated the Nue of Mount Hiei.
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.
Forged an item.
Changed the appearance of an item.
Completed "Deep in the Shadows."
Used the mask of an ugly fellow to defeat an enemy.
Reached level 10.
Bathed in first hot spring.
Completed "The Man with the Guardian Spirit".