Headcanon that Sekiro and Issihin were lovers (hence the long dialogues reminiscing over Sake), Isshin’s disguise as Tengu in order to conceal the fact Isshin couldn’t be seen with Sekiro as lovers (shirtless of course). Which makes the final battle even harder because the words “hesitation is defeat” is exactly what Isshin had told Wolf over drinks when Isshin was confessing his love for him. Hesitation to find love within Isshin, to stop the killing and to prevent shura.

Even under the golden sun, in Buddhism gold represents enlightenment, love, and purity, the clouds obscuring those parts of gold represent Sekiro’s demise and fall to Shura, but they also could be a metaphor for Wolf’s hesitation to actually love Isshin fully. He had to kill Emma because it was his way of fully abandoning that relationship with Isshin, his trust, his love gone but in the end Isshin says “I couldn’t bring myself to hate you”