Sekiro: Shadows Die Twice - Every Ending Explained (And How To Get Them)
2. Return - How To Get It
By far the most complicated ending is Return, so buckle up. For this you need to have spoken to the Divine Child in the Inner Sanctum and consumed (or given away) three of the rice balls she gives you throughout the game. After that, she'll get sick and request a persimmon so she can get better, which you might have found while exploring, but if not can be bought from the merchant near the Shugendo idol.
After this she'll give you a special item called Rice for Kuro, which you need to give to the Lord. He'll tell you how much he enjoyed it, and if you rest and speak to him again, will give you yet another special rice ball. Eat it and report back to the Divine Child.
Then you need to go diving underwater once you've beaten the Corrupted Monk, in the pond near the Temple Grounds idol and grab the Holy Chapter: Infested item. Give that to the Divine Child, rest, and meet her in the Halls of Illusion, where she'll tell you to find the Holy Chapter: Dragon’s Return. Head back to the Inner Sanctum, and up the steps to get back to Senpou. Follow the path into a cave just past the idol, and look for a skeleton holding an item, which is the second Holy Chapter.
From here you need two snake Viscera. The dried one can be found past the merchant in the poison swamp in the Sunken Valley. Enter the cave there and sneak past the snake until you see a single enemy. Hit him with the mind-control ninjutsu technique and jump up into the shack to find the item. The other item comes after defeating the Great Serpent, which can be accessed after finishing a side quest involving a kite in the first area of the Senpou Temple and performing a jumping deathblow.
When you have both of these ingredients, give them to the Divine Child. Travel back to Kuro and exhaust his dialogue and then return to the Divine Child, who will give you the Frozen tears. From here, beat the Dragon and the final two bosses as normal, and when interacting with a wounded Kuro, select 'Give Dragon Tears and Frozen Tears'.