Finally figured out what exactly you need to do to have Sekiro recognize the Sculptor. Most likely, you’ll need to complete Hirata Estate and ask the Sculptor what he sees. You also need to make sure you die quite early in the game, then eavesdrop through the hole at the back of the Dilapidated Temple on the Sculptor and Emma’s conversation while she collects his blood. Then progress to heal the Dragonrot. Might be a good idea to give the Sculptor his “tea” afterward. After defeating Gyoubu, be sure to speak with the priestess in the fortress where the Tengu of Ashina appears. Continue as normally until the first incursion by the Red Guard (after collecting the aromatic flower, the shelter stone, and the Mortal Blade, and prior to defeating the Divine Dragon). HOWEVER, if you are following the steps toward the Purification ending/you just want to fight Owl again, do NOT speak to Emma when she checks on the old graves just yet. First, head to the Dilapidated Temple and Emma should appear sitting next to the Sculptor, saying she often comes to listen to the sound of Buddha being carved. Eavesdrop from the back of the building again, and you should hear Emma telling him the Interior Ministry has arrived, and she will ask him if he still sees flames. Rest at the idol so that Emma leaves, then talk with the Sculptor. He’ll immediately tell you that it has to be you to kill him, not Emma. (This is why you have to do this step prior to speaking with Emma by the old grave—if you speak to her there, she relocates to the Dilapidated Temple permanently, and the Sculptor will not give this crucial dialogue if she is present.) Progress to the second incursion (after defeating Divine Dragon), and warp to the Dilapidated Temple. Speak with the info broker until he mentions that the Sculptor left muttering about the flames. Then you should be good to go! Continue to the Demon of Hatred, and when the boss fight initiates, Sekiro should address him, “Sculptor,” as well as some other dialogue during the fight, and then you can speak to the priestess and hear the alternate dialogue. What purpose does all this serve? Nada. It’s just a convoluted, but strangely satisfying, change of events. Hope this helps… Not sure if you need to give Emma any sake, but she does mention when you give her Unrefined sake that she “would want to kill a demon if one should appear.” I would have her drink it just in case.