The Strongest Mercenary's Guide to Conquering Isekai Dungeons

During a routine mission, Hasumi Ryuji—known as the strongest mercenary—is suddenly transported into the heart of an otherworldly dungeon. Greeted by a mysterious voice echoing in his mind and calling him a hero, he immediately finds himself face-to-face with monsters attacking local adventurers. Without hesitation, Ryuji subdues the threat using nothing but a single knife. When the situation escalates, he utilizes a unique item system to summon modern firearms, taking down a fearsome dragon by sniping its weak point with just one shot. Stunned by his overwhelming display of power, his bewildered new companions demand to know who he really is. Ryuji simply brushes off their shock, claiming to be nothing more than an ordinary soldier. However, his former life as an elite special forces operative has forged both his body and his tactical mind into ultimate weapons. Even mythic-tier dungeons prove to be no match for his unparalleled combat prowess and strategic brilliance. The ultimate conquest of another world's deadliest labyrinths by a former special forces mercenary begins now.