Conditions to Fight "Moon Cocoon Candice"

Speaking of which, I've posted about fighting "Moon Cocoon Candice" before, but I realized I never wrote about the conditions to make it appear. It seems it doesn't show up just by playing normally. You need to obtain the "Key of Time" found along the way and forge it using "Soul Crystals" to create the "Restored Key of Time"! (I don't know the appearance conditions based on difficulty. I fought it on Nightmare Layer 3.) This is probably the condition to fight Candice. Since the final stage quest of the current collaboration event should be to defeat Moon Cocoon Candice with "The Little Knight," I hope this helps.