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