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 Master Ninja" on Way of the Strong or higher.
Completed "The Grand Tournament" on Way of the Strong or higher.
Completed "Hands of the Dragon."
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.
Defeated the Onmoraki during "Resentment Unleashed."
Completed "Resentment Unleashed."
Made a total of 60 requests at the blacksmith.
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.)
Completed 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Completed "Scion of Virtue."
Completed any mission while transformed into a woman.
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.
Listened to Katakura Shigenaga's entire introduction in "The One-Eyed Dragon's Castle."
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 "Spirit Stone Huntress."
Acquired 40 gestures.
Communicated with a yokai 10 times.
Collected all the best materials.
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."
Acquired mystic art for the odachi.
Acquired mystic art for the dual swords.
Changed your hair style or beard.
Made two circuits around Japan.
Completed "The Queen's Eyes."
Defeated Derrick the Executioner.
Bathed in every hot spring from the Kyushu Region to the Omi Region.
Used the mask of an ugly fellow to defeat an enemy.
Completed "The Demon King Revealed."
Obtained first divine item.
Acquired mystic art for the sword.
Acquired mystic art for the spear.
Collected all Kodama from the Kyushu Region to the Omi Region.
Acquired mystic art for Onmyo Magic.
Acquired mystic art for the tonfa.
Acquired mystic art for Ninjutsu.
Acquired mystic art for the axe.
Completed "The Samurai from Sawayama."
Acquired mystic art for the kusarigama.
Completed "The Source of Evil."
Reached level 100.
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.
Changed the appearance of an item.
Used a disguise.
Collected all fragments of the Hiragumo teakettle from Shigisan.
Completed your first Twilight mission.
Completed "The Ocean Roars Again."
Lit all three evil-warding bonfires in Itsukushima.
Confused an enemy for the first time.
Completed "Deep in the Shadows."
Bathed in first hot spring.
Forged an item.
Reached level 10.
Completed "The Man with the Guardian Spirit".