My Legend as an Evil Hero in Another World

Ryuji Shinozaki, a 25 years old animator suddenly transported to a different world. He later on found out that the world he's in is a fantasy world and the sages there cast a summoning spell often to summon a hero. Because of the separation of him from his lover, he refused to save the world as well as to fight the forces of evil, this was later fueled by witnessing a very cruel scene. His adventure that is originally to save the world suffers a great turning point. Will he save the world and humanity as inscribe in the prophecy or something off tracks?...After all, he was just an average guy who was summoned there, nothing more, nothing less.