If anyone's having trouble here's my advice. Overall, the best strategy for this fight is to keep up the pressure and posture kill each phase. I realize it's much easier said than done, however chipping away at his health bar for 20 minutes will only lead to more frustration. With this strategy, I beat the Sword saint in around 2 dozen attempts, so don't feel bad if you keep losing. Anyways, here's how I beat the Sword Saint: Phase 1: Immediately run behind Genichiro and hit him once. If he goes for a second mortal blade attack get behind him once again and hit him twice. If he doesn't go for a second mortal blade attack, then hit him a second time. After this, it's business as usual for Genichiro. Parry the crap out of him and be as aggressive as possible. Your best friend here is his wombo combo which you can deflect. He will follow this up with a thrust which you can then Mikiri counter. This absolutely destroys his posture. With this strat, I usually have Genichiro down with only one or two hits taken. Phase 2: Immediately after the phase transition pop a pellet If you left phase 1 with >75% HP or a gourd chug if you left with less HP. Then wait for him to strike first and deflect. The stat I found most effective for this phase is a combo of R1+R1+L1. Repeat this until he does one of his perilous attacks. Generally speaking, running out of their range works best. His Ashina Cross and thrusts are your best friends as in the case of the Ashina Cross, you can run behind him and get a couple of free vitality hits. The thrust is free posture damage via Mikiri counter. If he does his wind attack, run out of its range and wait for his next attack. He will also follow up his Ichimonji with a sweep so I recommend just running out of range of that one as well. Phase 3: IMMEDIATELY after getting the first deathblow on Isshin, run to where you believe is an optimal position in the arena to continue the fight. The last thing you want is to be pinned up against a wall or the cliff edge. Pop a Gokan's Sugar/Spiritfall as soon as you can as well. My best advice for this phase is to parry everything and run in a circle if he pops his Glock on you. If he does the wind attack, run out of range of the attack and wait for one of his overhead slams. Like before, thrusts are your best friend as they are essentially free posture damage. Also, and this is EXTREMELY important: NEVER try to back away and heal. Instead, parry some attacks and wait for a break or better yet, a thrust. Phase 4: More of the same, except his wind sweep now has lightning. It's up to you whether you feel confident enough to do a lightning reversal. It's a massive risk/reward move, though if successfully pulled off you gain a massive window for insane posture damage. Also, the phase transition is super short so I would recommend just waiting for an overhead slam or thrust to heal like earlier. TL;DR: Be as aggressive as possible and only heal when you've successfully countered a combo.