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.)
Completed "The Grand Tournament" on Way of the Strong or higher.
Completed "The Master Ninja" on Way of the Strong or higher.
Acquired mystic art for the odachi.
Acquired mystic art for the kusarigama.
Acquired mystic art for the axe.
Acquired mystic art for the spear.
Acquired mystic art for the dual swords.
Acquired mystic art for the sword.
Acquired mystic art for Onmyo Magic.
Acquired mystic art for Ninjutsu.
Defeated the Onmoraki during "Resentment Unleashed."
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 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Completed "Resentment Unleashed."
Completed "The Sanada's Resolve."
Completed any mission while transformed into a woman.
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.)
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.
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 "Hands of the Dragon."
Completed "Spirit Stone Huntress."
Completed "The One-Eyed Dragon's Castle."
Bathed in every hot spring in the Tohoku region.
Collected all Kodama 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."
Acquired mystic art for the tonfa.
Reached level 100.
Completed "Yokai Country."
Reached level 10.
Completed "The Queen's Eyes."
Made two circuits around Japan.
Defeated Derrick the Executioner.
Collected all the best materials.
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."
Changed the appearance of an item.
Acquired 40 gestures.
Used a disguise.
Completed "The Source of Evil."
Used the mask of an ugly fellow to defeat an enemy.
Completed your first Twilight mission.
Witnessed Tokugawa's forces head toward a decisive battle.
Became Ryunoshin the dung lover's best friend.
Met with Tokugawa Ieyasu.
Made a total of 60 requests at the blacksmith.
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.
Confused an enemy for the first time.
Collected all fragments of the Hiragumo teakettle from Shigisan.
Communicated with a yokai 10 times.
Completed "The Ocean Roars Again."
Lit all three evil-warding bonfires in Itsukushima.
Changed your hair style or beard.
Forged an item.
Completed "Deep in the Shadows."
Bathed in first hot spring.
Completed "The Man with the Guardian Spirit".