Eoreobuteun Dari Naeryeoanjeun Got

The Empire’s only Swordmaster, Raviruth Penhac, is afflicted with a strange condition—he's possessed by spirits every night. While running a mercenary group on the frontier, one day he scouts a genius boy named Sel. Raviruth, who had never shown interest in any woman, suddenly starts reacting—to Sel. "What the hell is happening? No way. There's no way I like guys!" But Sel, who joined the mercenary group while hiding her true gender, starts to become conscious of Raviruth as he gets closer to her… (Source: Bomtoon, translated)