The Villainess and the Demon Knight manga volume 4 features story by Nekota and art by Seikan.

Cecilia has been reincarnated as the villainess of a dating sim. Now she's married to dangerous Lord Lucas, and her nights are now filled with lustful passion. While the two of them enjoy their newlywed status, Lucas's brother, Prince Leon, has his own wedding plans. The brothers must head to the desert country of Magyar to welcome Leon's future bride. Left alone, Cecilia finds herself unexpectedly playing hostess to the Magyar's handsome prince Akim. This will put her diplomacy skills to the ultimate test!