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 any mission while transformed into a woman.
Defeated Ganryu's Sasaki Kojiro using only Dual Wooden Swords. (Cannot use a Visitor/Companion.)
Completed "The Grand Tournament" on Way of the Strong or higher.
Completed the 20th plane in The Abyss.
Equipped +15 divine equipment in all slots. (Excludes accessories.)
Bathed in every hot spring from the Kyushu Region to the Omi Region.
Collected all Kodama from the Kyushu Region to the Omi Region.
Acquired mystic art for the axe.
Collected all fragments of the Hiragumo teakettle from Shigisan.
Completed "The Master Ninja" on Way of the Strong or higher.
Bathed in every hot spring in the "Siege of Osaka (Summer)" chapter.
Acquired mystic art for Ninjutsu.
Acquired mystic art for the spear.
Acquired mystic art for Onmyo Magic.
Completed "The Last Samurai."
Collected all Guardian Spirits.
Defeated all types of yokai.
Collected all Kodama in the "Siege of Osaka (Summer)" chapter.
Destroyed all the Revenant contraptions on "The Last Samurai."
Communicated with a yokai 10 times.
Completed "Resentment Unleashed."
Defeated the Onmoraki during "Resentment Unleashed."
Acquired 40 gestures.
Completed 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Acquired mystic art for the tonfa.
Acquired mystic art for the odachi.
Bathed in every hot spring in the "Siege of Osaka (Winter)" chapter.
Completed "The Sanada's Resolve."
Destroyed all the destructible cannons in "The Sanada's Resolve."
Completed "The Sparrow Flies Again."
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."
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."
Acquired mystic art for the dual swords.
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."
Completed "Yokai Country."
Acquired mystic art for the kusarigama.
Used a disguise.
Made a total of 60 requests at the blacksmith.
Made two circuits around Japan.
Completed "The Queen's Eyes."
Defeated Derrick the Executioner.
Collected all the best materials.
Completed "The Demon King Revealed."
Obtained first divine item.
Reached level 100.
Completed "The Samurai from Sawayama."
Completed "The Source of Evil."
Acquired mystic art for the sword.
Witnessed Tokugawa's forces head toward a decisive battle.
Became Ryunoshin the dung lover's best friend.
Used the mask of an ugly fellow to defeat an enemy.
Found Muramasa and brought him in.
Met with Tokugawa Ieyasu.
Changed the appearance of an item.
Reached maximum proficiency with your first weapon.
Changed your hair style or beard.
Completed your first Twilight mission.
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.
Confused an enemy for the first time.
Forged an item.
Completed "Deep in the Shadows."
Bathed in first hot spring.
Reached level 10.
Completed "The Man with the Guardian Spirit".