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!
Equipped the Kusanagi Tsurugi, Yasakani Magatama, and Yata Mirror.
Completed the 20th plane in The Abyss.
Completed "The Master Ninja" on Way of the Strong or higher.
Completed "The Grand Tournament" on Way of the Strong or higher.
Completed "The Sparrow Flies Again."
Made a total of 60 requests at the blacksmith.
Completed "Hands of the Dragon."
Used the mask of an ugly fellow to defeat an enemy.
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.
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.)
Equipped +15 divine equipment in all slots. (Excludes accessories.)
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.
Communicated with a yokai 10 times.
Completed the mission "The Siege of Osaka (Winter)."
Defeated Sarutobi Sasuke in the mission "The Siege of Osaka (Winter)" using only tonfa. (Cannot use a Visitor/Companion.)
Used all the culverins in the mission "The Siege of Osaka (Winter)."
Completed "Spirit Stone Huntress."
Listened to Katakura Shigenaga's entire introduction in "The One-Eyed Dragon's Castle."
Completed "The One-Eyed Dragon's Castle."
Bathed in every hot spring in the Tohoku region.
Collected all Kodama in the Tohoku region.
Seized all of Aoba Castle's three-storied keeps in "The One-Eyed Dragon's Castle."
Completed "Yokai Country."
Defeated Derrick the Executioner.
Collected all the best materials.
Acquired mystic art for the kusarigama.
Acquired mystic art for the tonfa.
Completed any mission while transformed into a woman.
Used a disguise.
Acquired mystic art for the spear.
Acquired mystic art for Onmyo Magic.
Acquired 40 gestures.
Acquired mystic art for Ninjutsu.
Acquired mystic art for the dual swords.
Acquired mystic art for the sword.
Acquired mystic art for the odachi.
Completed 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Confused an enemy for the first time.
Made two circuits around Japan.
Completed "The Queen's Eyes."
Completed "The Demon King Revealed."
Obtained first divine item.
Collected all Kodama from the Kyushu Region to the Omi Region.
Bathed in every hot spring from the Kyushu Region to the Omi Region.
Completed "The Samurai from Sawayama."
Reached level 100.
Completed "The Source of Evil."
Acquired mystic art for the axe.
Witnessed Tokugawa's forces head toward a decisive battle.
Became Ryunoshin the dung lover's best friend.
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.
Collected all fragments of the Hiragumo teakettle from Shigisan.
Completed "The Ocean Roars Again."
Lit all three evil-warding bonfires in Itsukushima.
Changed your hair style or beard.
Completed your first Twilight mission.
Changed the appearance of an item.
Forged an item.
Completed "Deep in the Shadows."
Bathed in first hot spring.
Reached level 10.
Completed "The Man with the Guardian Spirit".