The Holy Knight's Dark RoadSeinaru Kishi no Ankokudou; 聖なる騎士の暗黒道

Description from JNC: Young Sain Forth has it made; as the famed Holy Knight, he has the peoples love, the respect of kings, and the blessings of a literal goddess. His aspirations lie elsewhere, though. With his assistant Melia at his side, he leaves for an academy in a foreign kingdom, where he is treated as a deviant by his peers. Its his own fault, mind youhis stubborn insistance on wearing a custom, all-black uniform makes him stick out. He isnt the only outcast in his class: Alicia, born into the Clan of Light but unable to use anything but fire magic, faces similar struggles, and the two quickly become allies. Alicia proposes that they enter the labyrinth below the school in search of a holy sword, but Sain has other plans in mind: a doom sword. And so, with his friends in tow, Sain ventures into the perilous unknown, driven by a wish to become the coolest, edgiest, most awesome thing in existence: a Dark Knight. Theres just one problem. He cant use dark magic. Like, at all. [Official English Translation of the Light Novel](https://j-novel.club/s/the-holy-knight-s-dark-road)