Black Summoner, Vol. 1 (manga)

Fight the strong and winif you cant do that, youre a weakling! A boy finds himself in a strange place, with no memory of his past. His name is Kelvin, and he soon discovers that hes been transmigrated to another world, giving up even his memories in exchange for extremely powerful abilities! Thus, he begins his journey as the worlds strongest Summonerchallenging one mighty adversary after the other, gathering allies, and discovering his calling as a true battle junkie!!