I watched a list of the "hardest Sekiro fights ranked in order" and was surprised they put snake eyes in Ashina Depths poison pit as harder than Sunken Valley one. The Sunken Valley one you have to do some motherfucking voodoo magic to get a stealth deathblow off, so without that it's a 2 deathblow fight whereas the Ashina Depths one you can literally just walk right behind her and get the stealth blow and then fight her for 1 lifebar in that cave she's in without any enemies being alerted and it's much easier since it's a 1 hp fight vs 2 hp.
The ranking was placing the ashina depths one higher simply because poison and other enemies joining the fight, but if you fight her in the cave neither of those apply so I think the Sunken Valley one is harder. Would've beat that one in a few attempts if it was only a 1 lifebar fight.
I'm also always surprised they put Genichiro in like the top5 or so in all these lists but I get that everyone has trouble at different bosses. Genichiro was probably like the easiest boss for me because it was like a normal fight with fair reach and recovery and posture damage and you just played the way the game had taught you to play and it wasn't bad. The 3rd phase I thought was the easiest since he does the lightning thing so much and if you know how to reverse it you get all the free damage and it's a dodge/run around and counter that twice and you're done kinda fight.
On era so many people who beat the game said Genichiro was the hardest and where the difficulty peaked and I just don't get it. I spent more time on the General guy on the stairs leading up to Ashina castle than Genichiro and Great Shinobi Owl is literally the Genichiro fight but way harder because he's got much longer range, does even more damage, is faster, does a ton more posture damage, and in phase 2 throws out the bullshit poison. I dunno how anyone can think Genichiro is harder than Owl, but again everyone has trouble with different shit. I had no problem with Guardian Ape phase 1, but tons of problems with phase 2 and a lot of people it was the opposite. Monk gave me a ton of problems, but O'Rin & Centipede man didn't.