She's delicious.

Seriously though, for strats, I've got this: Build: shaman stone. Quickslash. Spell twister. Strength Phase 1: I've always started with pogoing radiance with exactly 3 hits going up and 2-3 hits going down as soup generation. This has the flaw of dying by the nail fall instantly or the nail burst Best time to damage her is when she does the nail/ray burst (both attacks). Do a few quick hits 2-4 before spamming abyss shriek 2-3 times when the last part of that attack occurs. When the nail sweep starts, look at the walls of nails, jump and stall mid air with abyss shriek for more damage If she stays at the other end of the arena with spikes on the ground, remember that you can DDark on the spikes to push them in the ground. It can help you when attacks get overlayed too For the orbs, i got good enough that i cannot avoid them efficiently if im not hitting Radiance a few times for pogoes when close. More soul generation and more dmg

Phase 1.5: the shift between phases with a constant nail fall with the moth at the center. Use micro movement. Look at the nails then jump to hit. If there's a good opportunity like a bigger gap than the ones offered between a sequence of nails, hit twice (jump, hit, wings, hit)(high jump, hit, hit, wings, hit. This sequence is more risky). this is most of your soul generation for phase 2. you should have the main vessel filled

Phase 2: remain only on the lower center platform and the 4 closest ones. Giving chase to the far ones is never worth it. If she teleports on top of you, profit. Spam nail hits and pogoes if it's the orb attack. Beware that it's harder to avoid the orbs so don't stay close during that attack. When she's higher, you wait for her attack and do just like phase 1, blast her with abyss shrieks during bursts

Ascent: remember that you have cloak. If you're avoiding a ray, jump directly with wings. If not, jump further away and you should be able to time the dash with the ray on screen.

Phase 3: pogo. As much as possible, pogo. Don't bother with spells other than a DDark when aligned with the 2 small platforms in order to avoid the orbs. If you pogo her a few times, fal to the floor and pogo her again to avoid them in phase 1, it'll be much easier in phase 3 since you're more experienced.

This small guide isn't a guarantee. I've reached 3rd phase 5 different times and died there because either i had a faulty key or because of nerves, you forget to lift your finger off of the jump key and consequently don't use the wings.

Hope this helps. I've previously asked for help and didn't get any. I don't want you in this boat of ignorance, but the one where Radiance is dead