Got her to about 25% today before I made a fatal mistake to not use a partial Burst during Rage. I feel like I could win if either I had more opportunities to practice, or there wasn't a time rush from debuffs falling off, preventing me from thinking my actions through. It's a very technical fight with kamihime I've never used before, and thus it's easy to make mistakes. I didn't use an elixir this time, preferring to save them for first clears on future Ragnaroks (when the event quest will make it worthwhile).
The strategy I used was effective, though it relied significantly on RNG and my particular rainbow combination of SSRs. It's probably not even worth explaining because of that.