Messiah: Isekai o Sukutta Moto Yuusha ga Mamono no Afureru Genjitsu Sekai o Musou suru

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...