This was my first attempt against her on the DLC so I had no idea what I was doing at the time but somehow managed to proc an insane amount of damage with Frostbite using the Dark Moon Greatsword/Helphen's Steeple combo.
extra:
elden ring
dark souls
renalla, twin moon knight
build
greatsword
spells
strength
intelligence
dexterity
shadow of erdtree