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!
Made a total of 60 requests at the blacksmith.
Completed the 20th plane in The Abyss.
Completed "The Grand Tournament" on Way of the Strong or higher.
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.
Defeated the Onmoraki during "Resentment Unleashed."
Became Ryunoshin the dung lover's best friend.
Bathed in every hot spring in the "Siege of Osaka (Summer)" chapter.
Destroyed all the destructible cannons in "The Sanada's Resolve."
Used the mask of an ugly fellow to defeat an enemy.
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)."
Bathed in every hot spring in the "Siege of Osaka (Winter)" chapter.
Defeated Ganryu's Sasaki Kojiro using only Dual Wooden Swords. (Cannot use a Visitor/Companion.)
Collected all the best materials.
Completed "The Sparrow Flies Again."
Completed "Hands of the Dragon."
Completed 10 missions with NPC or in the “Yokai Realm with a companion” with other users.
Forged an item.
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."
Collected all Kodama from the Kyushu Region to the Omi Region.
Completed "Resentment Unleashed."
Collected all Kodama in the "Siege of Osaka (Winter)" chapter.
Completed "The Sanada's Resolve."
Completed "Scion of Virtue."
Defeated all of Sanada's Ten Braves in "Scion of Virtue."
Completed the mission "The Siege of Osaka (Winter)."
Completed "Spirit Stone Huntress."
Changed your hair style or beard.
Acquired mystic art for the tonfa.
Acquired mystic art for the kusarigama.
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."
Acquired mystic art for Ninjutsu.
Acquired 40 gestures.
Acquired mystic art for the spear.
Acquired mystic art for the axe.
Completed "Yokai Country."
Acquired mystic art for the sword.
Made two circuits around Japan.
Completed "The Queen's Eyes."
Defeated Derrick the Executioner.
Acquired mystic art for Onmyo Magic.
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.
Completed "The Source of Evil."
Completed any mission while transformed into a woman.
Used a disguise.
Acquired mystic art for the odachi.
Acquired mystic art for the dual swords.
Communicated with a yokai 10 times.
Witnessed Tokugawa's forces head toward a decisive battle.
Met with Tokugawa Ieyasu.
Found Muramasa and brought him in.
Changed the appearance of an item.
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.
Completed your first Twilight mission.
Collected all fragments of the Hiragumo teakettle from Shigisan.
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".