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.
Completed any mission while transformed into a woman.
Completed "The Grand Tournament" on Way of the Strong or higher.
Equipped +15 divine equipment in all slots. (Excludes accessories.)
Completed "The Master Ninja" on Way of the Strong or higher.
Collected all the best materials.
Bathed in every hot spring in the Tohoku region.
Defeated the Onmoraki during "Resentment Unleashed."
Bathed in every hot spring 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."
Collected all Kodama in the "Siege of Osaka (Summer)" chapter.
Completed "Resentment Unleashed."
Completed "The Sanada's Resolve."
Destroyed all the destructible cannons in "The Sanada's Resolve."
Completed "The Sparrow Flies Again."
Made a total of 60 requests at the blacksmith.
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.
Acquired mystic art for the odachi.
Acquired mystic art for the kusarigama.
Acquired mystic art for the axe.
Acquired mystic art for the tonfa.
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)."
Acquired mystic art for the dual swords.
Completed "Hands of the Dragon."
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."
Collected all Kodama in the Tohoku region.
Seized all of Aoba Castle's three-storied keeps in "The One-Eyed Dragon's Castle."
Became Ryunoshin the dung lover's best friend.
Completed "Yokai Country."
Acquired 40 gestures.
Acquired mystic art for Ninjutsu.
Made two circuits around Japan.
Completed "The Queen's Eyes."
Defeated Derrick the Executioner.
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.
Acquired mystic art for Onmyo Magic.
Completed "The Samurai from Sawayama."
Reached level 100.
Collected all fragments of the Hiragumo teakettle from Shigisan.
Communicated with a yokai 10 times.
Completed "The Source of Evil."
Acquired mystic art for the spear.
Acquired mystic art for the sword.
Witnessed Tokugawa's forces head toward a decisive battle.
Completed 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Reached maximum proficiency with your first weapon.
Met with Tokugawa Ieyasu.
Found Muramasa and brought him in.
Used a disguise.
Used the mask of an ugly fellow to defeat an enemy.
Completed "The Demon of Mount Hiei."
Defeated the Nue of Mount Hiei.
Completed "The Ocean Roars Again."
Lit all three evil-warding bonfires in Itsukushima.
Changed your hair style or beard.
Confused an enemy for the first time.
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".