My Japanese is basically non-existent, but if what little I've picked is correct...
I dub thee Kenshin no Yuri!
Which, I think/hope, loosely translates to Knight of Girl Love.
So basically, Prince Prickface went "The Saintess is fake, her powers are nothing."
Princess Saintess therefore went "Welp, looks like they don't need me to keep up this MASSIVE fucking barrier that's continiuously draining my power."