How to beat the crumbling-city Elden Ring boss in phase two?

[Daniel_R]

I've hit a wall with a certain late-game boss in Elden Ring, the one in the crumbling city who has a devastating second phase with relentless aerial attacks. I'm playing a strength-focused build with a greatsword and a medium shield, and I can consistently get through the first phase, but I'm struggling to find openings to attack in the second without getting punished. For those who have conquered this fight, what's your Elden Ring boss guide for this specific encounter? Are there any particular weapon arts, spirit ashes, or consumables that trivialize the second phase, and what's the best strategy for dodging the combo that ends with the ground slam?