Hero Dawner and his party take three trap-ridden paths that end up leading them all the way back to Goodreste, which undermines the whole point of capturing Princess Syalis. The Demon King wants to fight the Hero, be he also wants the Hero to have a sporting chance.
As the Big Ten Demons discuss all the means by which they’ll lure the Hero to them and level him up (if he ever makes it there), Sya ends up using those to wash a blue stain out of her comforter. She sullies the Fountain of Purity, uses a mini tornado bomb to agitate the washwater, uses the Magnespear as a drying rack, and uses Professor Gearbolt’s new mecha as a spin dryer.
When the seasons start to change and a chilly wind enters her chamber, Syalis realizes she left her prized woolen underwear at home, and so must make new ones. Again, given adequate motivation, she’ll stop at nothing and spare no demon’s welfare to achieve her quests goals.
That said, she remembers her mother telling her as a kid not to lift up her skirt to reveal her undies, nor mention them to anyone, in order to preserve her dignity and that of the crown. As a result, she uses various non-verbal forms of code to try to express to the demons what she’s making. They misinterpret her code and go on high alert, believing she’s creating some kind of weapon to destroy the castle. But nope…she just wants a warm stomach at night!
All this chaos, and Hero’s inability to arrive and get this confrontation over with, has the Demon King in a constant state of anxiety and insomnia, collapsing in front of Syalis’ cell door. While she momentarily considers “finishing him off” with her giant scissors, she instead tries several methods to put him to sleep, none of which remotely work.
That is, until he asks her what she does to fall asleep, and again she remembers what her mom did for her. She pats the Demon King gently on the head until he nods off, then falls asleep beside him until her plush bears carry her off to her bead.
And so without any meaningful action from the Hero, Syalis has successfully neutralized the Demon King and his court. There’s really no coming back from his present drop in credibility as a villain. For cryin’ out loud, he was head-patted to sleep by his supposed hostage!