On top of energy inversion, the debilitated rod and the skill gained by meditating on a fouslet's essence provide reliable means of stunlocking bosses, as well as being nice for magical atk builds
I'm going to be honest. i have the setting to very easy and I still can not beat Serenata. I use fire and get her down and then she just uses her magenta powers to over power me or heals herself all the way. I try the energy set and heal myself and I can barely get her down to half before I lose focus and cum to lose...
isn't she easy? i think i beat every boss with cristal mod? (which doubl your magic attack and increase mana cost) and on very easy i haven't any problems.. if it still difficult for you, you can farm mob in forest near witch house she will facesit on your face and give you 1 lvl aslo after some time or after you beat her you would be able to choose this option in dialog
Try downloading this and putting it in the www\img\pictures folder.
Make sure it's named "WIA_1" and doesn't include whatever random character F95 adds.