Ending #1 – Shura
Shura is the fastest possible ending in Sekiro. After defeating Guardian Ape and the purple glowing Corrupted Monk you will have to head back to Ashina Castle where Great Shinobi Owl awaits you at the rooftop. After talking to him you will have the choice to either obey him or Kuro. Choose the option to obey Owl.
This triggers two boss fights and you will receive the Shura Ending.
This also unlocks the Shura trophy or achievement.
Ending #2 – Purification
Just as the first ending you will have to reach the rooftop with the Owl. This time stay loyal to Kuro and defeat Owl instead. Follow those steps to unlock it:
1. After defeating Owl head to Isshun’s place and eavesdrop on him and Emma
2. Eavesdrop on Kuro from behind a corner in his room
3. Rest and head upstairs to talk to Emma about Kuro, agree with her
4. Rest and talk to her again
5. Head to Old Grave Idol, go left immediately to the graves and talk to Emma again
6. Head to Sculptor Place and eavesdrop on both of them from behind the building
7. Confront Emma and receive a bell from her which you use at the Buddha statue again
8. Head to the same room Lady Butterfly was in
9. Beat Owl – Good Luck with that
This unlocks the Purification trophy or achievement.
Ending #3 – Immortal Severance
Just as the 2nd ending you will have to reach the rooftop with the Owl. Stay loyal to Kuro and defeat Owl instead, but this time do not head to the second version of Hirata Estate! Instead, from there you will simply have to follow the story until the end without returning to Hirata Estate.
Ending #4 – Return
Just as the other endings you will have to reach the rooftop with the Owl. Stay loyal to Kuro and defeat Owl instead. From there you will simply have to follow the story until the end with a few things you have to do before finishing the last boss.
Gather both Serpent Fruits (fresh and old one) from the Giant Serpents. For the old one head to the area before the Guardian Aboss fightght, but instead of going in the direction of the Ape, go to the very bottom of the area in another direction. You will reach a cave with the Giant Serpent in it. There follow the path until you can see its head. Drop down on the left side and use Puppeteer Ninjutsu on the monkey and it will distract the snake for you. Head through the door there and pick up the Old Fruit.
For the Fresh Fruit head to the Senpou Temple and drop down to the right of the exit of the first Idol in the area. There you will see a mechanism for a kite and a small enemy next to it. Use Puppeter Ninjutsu again on this small guy and he will operate the kite for you. Follow the path until you can grapple to the kite and it will transport you to a new area from which you can kill the Giant Serpent. Fresh Fruit is yours.
The second step for the ending is the Divine Child in Inner Sanctum. You will have to give a scroll you will find by diving in the pond in the Temple Ground, she will disappear into the illusion where you chased the monkeys.
Find her again in the Ilussion where you fought the 4 small monkeys. Talk to her and she will return to the Inner Sanctum and will tell you about the fruits. She will tell you to find the monk who is in the dark cave next to the temple you are in. Find him there and bring what you got from him back to her. Now you can feed her the fruits. You will receive frozen Dragon Tears from her which you will have to use at Kuro after defeating the last boss in the game.
Note: If a sequence with the Divine Child won’t trigger try to rest at an Idol, feeding Rice to Kuro and coming back, or simply progressing the story a bit further. Some people have troubles triggering events with her for yet unknown reasons, but this is basically what you have to do for the ending. This is basically the Sekiro Secret Ending as it has the most steps to it and is the trickiest to get.