Manga Like Game Chishiki de Saikyou ni Natta Mob Heishi wa, Shin no Jitsuryoku wo Kakushitai

A lowly gate guard, just another nameless soldier—but secretly, he was the strongest soldier!? One day, Silva realizes he's been reborn as a mob soldier in the very game he was obsessed with in his previous life. To survive in this dangerous world, he uses his game knowledge to become incredibly strong, but hides his true power to avoid altering the game's storyline. However, by chance, he easily cuts down a powerful demon that even the hero struggles against. And, what's more, he does so right in front of his favorite heroine…! From that moment, word of his strength gradually begins to spread—!? A heroic fantasy where the strongest mob soldier unleashes his full potential for the sake of his favorite character!