Boris Marks

Boris Marks is a minor supporting character in How NOT to Summon a Demon Lord (also known as Isekai Maou to Shoukan Shoujo no Dorei Majutsu).

He is an infantryman serving in the Kingdom of Lyferia's Faltra stationed troops at Fort Bridge Ulug, part of the Thirteenth Regiment. Boris appears as a soldier who encounters the protagonist Diablo (Takuma Sakamoto in his Demon Lord form) early on, nervously stopping him to inquire about his identity and intentions while on duty. He is depicted as dutiful and somewhat intimidated in the presence of powerful figures.

Later appearances (especially in the light novels) show him involved in reconnaissance duties, such as scouting for threats like the Demon Lord's army alongside his friend Massa. He's portrayed as embodying traits of an ideal knight—courageous and dedicated—helping motivate Diablo to defend the fort during key conflicts like the assault by the Fallen.

Overall, Boris is a background military character who helps highlight Diablo's overwhelming presence and the story's fantasy war elements.