Prince's brother is set to kill the Greataer Demon Lord lurking in the border region's ruins. As the first prince of the Royal family he's trying to one up his brother to show he's fit to rule the country. Prince's brother surround a Lamia and just as he's about to kill it Prince stops him. His reasoning? Tits. The trio take down the soldiers and only they and the Lamia stand. 

The trio try to coerce the Lamia to have sex but she's not having it until Wizard gives her a medicine that transforms her to have human legs but most importantly it also acted as aprodisiac. Pig starts to fuck her intact tail as he knows Wizard and Prince won't let him fuck her first. They take pity by letting him use her mouth first but she ends up biting his dick/sucking his blood. 

Prince and Wizard do their thing and tell Burako to take care of her. She appears to be in a maid uniform and is only there as she couldn't find a job after they killed her boss the Demon Lord. They also lied and said the Greater Demon Lord killed Prince's brother and they killed it. Prince is now the ruler of the country.