Jek

Jek is a high-ranking vampire serving under the Vampire King Nesta, tasked with seizing the forbidden grimoire by leading his subordinates into battle. Despite his glamorous appearance and fondness for elaborate dress, he is a ruthlessly dangerous figure who stops at nothing to achieve his goals—having ambushed the protagonist Rikka and coldly taken the life of her closest friend Azuna. As the primary rival to the demon forces, Jek stands as one of the story's most formidable antagonists.