Tensei Colosseum: Saijaku Skill de Saikyou no Onna-tachi wo Kouryaku Shite Dorei Harem Tsukurimasu

Overview

The story begins when high school boy Mikagami, whose only redeeming feature is his skills in video games, is summoned to a different world. He has only the weakest skill "Copy" and, for being useless, he is turned into a sword-fighting slave in the coliseum. Mikagami is pale in the face of the coliseum, where the worst punishment is that "the loser becomes the winner's slave and is mated". The story depicts how he uses his weakest skill "Copy" with the confidence that he has never lost in a "game" before, and how he manages to defeat the stronger players in a duel as if it were a game. (Source: Comic Natalie)

Source: AniList