Meanwhile, I have 49 shrines, 10 lightroots, 12 koroks, and I'm at Hyrule Castle getting my butt handed to me by the two groups of five Phantom Ganons you have to fight. I made it to the second phase and the entire floor got covered in gloom because I evidently didn't realize that some of them will start spreading it unless you attack them. As you can probably tell, I've been trying to see how far I can get without going out of my way to explore and find more shrines/seeds/whatever else buffs you, and it's been rough at times, but this might finally be too much for me. I should try to exchange some of my stamina for hearts, since I probably don't need the former as much at this point and have max stamina with only one extra heart (beyond the ones you get from beating the temples and such).
Update: never mind, got it the next try (though I had to eat a lot of apples).