The main plot of 'Beauty Sage and the Devil's Sword' light novel could be complex. It may start with the discovery of the devil's sword by the beauty sage. As she holds the sword, she might start to experience strange visions or gain new powers. Along the way, she may face opposition from those who fear the power of the sword or want to use it for their own evil purposes. She might also have to form alliances with other characters, like a mysterious warrior or a wise old mage, to understand the true nature of the sword and how to control it. And perhaps, in the end, she has to make a difficult choice between using the sword's power at a great cost or finding another way to defeat the ultimate evil that threatens her world.
I haven't read it, so I can't be certain. But it might be about a sage who has some sort of connection to a devil's sword. Maybe they have to master the power of the sword for a greater good, like saving their world from an evil force.