The Savior <<Messiah>> ~The former hero who saved another world beats the real world full of monsters~ is a Manga/Manhwa/Manhua in english language, MONSTERS series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The "former" savior, Takeru Yamato, was summoned to another world and executed because of his strength. When he wakes up, he finds himself in Japan, where he spent time before being summoned. However, in the city, demons appearing from "gates" rampage, and those called hunters fight using magic. Returning from another world, Takeru decides to hide his powers and live, but...