Man, that boss in 'Elden Ring' had me tearing my hair out for days! I swear, every time I thought I had their pattern down, they'd pull out some new brutal combo. The key for me was patience—no greed. I'd chip away at their health little by little, always keeping enough stamina to dodge. Learning their tells was huge too; that slight windup before the big swipe saved me more times than I can count.
Another thing that helped was experimenting with different weapons. My trusty greatsword was too slow, so I switched to a quicker curved sword and suddenly I could get in hits between their attacks. Summons also made a world of difference—Mimic Tear especially, since it basically gave me a second chance to learn the fight while it tanked. Now when I face that boss on new playthroughs, it's almost nostalgic how much smoother it goes.