Reincarnation of the Suicidal Battle God

Humanity’s strongest regression action fantasy.
“Even if the disgusting gods did it, they still gave the opportunity. if you want to wedge you have to kill them”.
Zephir, the last survivior of mankind. The lonely battle with demon lord ended id defeat, but the opportunity given by the gods bring us back 10 years ago.
The gods who treated demons and humans as a shit.