I fairly quickly got to the point where I could deal down Gen and/or first bar without taking much damage. But that wasn't constant.
By the end I'd say Gen was weirdly way worse than the first bar. A lot of my time fighting the boss was wasted on false starts with Gen, where I'd just casually deflect really well and then run right into a thrust I meant to Mikiri, and it would fuck me over. Sometimes I'd recover but sometimes it would doom it already. So I would just accept death, etc.
First phase's attacks took a bit to learn but it was easy enough patterns. Compared to most other bosses, it was easier for me to see what attacks he did together, considering there were usually only a few hits? Get knocked back, Mikiri (and when this messed up I'd at least weirdly dodge into him, vs Gen's landing); he charges and goes forward, jump and punish the sweep. I'd attack till he deflected, I'd deflect his 3 hits. Etc. Of course, having said all that, in reviewing the video I saved, I guess I blocked out that he totally killed me early in the the first bar on the winning run, lmao.
Would confetti + ako at start of bar 2. This was definitely the worst of it for me. I could deflect most ok but there was a lot of hits I'd just eat. The worst was the thrust- I'd fucking constantly think it was a sweep for some reason, and jump right into it. Even the last time, I'd been countering it well but had some bad luck - accidentally went into Ichimonji Double, which broke him but I couldn't follow it up because he hit me back right as it happened, so I had to keep fighting - and then he used it and I foolishly ate it one last time before I got the blow.
Then bar 3 was... not worse? Certainly the lightning could be bad, but turning it against him helped. Just had to hold on enough to finish things; I only ever got here a few times, and often was completely out of healing. The time I got closest before the win, I had bad luck... used a jizo (for the first time?) only to immediately die, then did well enough until I took a bad hit and went flying over the edge. It was... frustrating. But the last time, it really did not feel that bad. Appropriately it reminds me of that extra Gen phase, where I also did not get to it much and just had to power through when I finally came into it with healing left.
In the end, I had 1/10 gourd left and I think 2 pellets even. Think I used confetti at start of bar 2 as usual and then twice more during 3, due to lightning wiping it. Had resurrected twice since he killed me again in the last bar. Used 17/18 emblems, mostly on Mist Raven just to give myself space after being hurt but some on Purple Flame Spark later on; I feel like I never got a good feel for what tools would serve me best. Snow, divine grass, jizo, bite down, etc. were unused this last time, which surprised me. Was expecting I'd have to use snow at least.
Overall... I certainly had trouble, but it was not a boss that dwelled in Camera Hell, and even bar 2 which I never fully learned did not feel ridiculous like some bosses could feel. The attacks generally were things I could read and respond to; more than most fights I felt like it was genuinely my fault for failing. So... I'm glad it ended on a fight that felt fair! I was just surprised since people made it seem way way more imposing, hmm.