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