Akudou Yuusha

The wrongful journey of anti-hero Algis and his party.
Algis hails from a long ancestry of heroes but really hates slaying monsters all day.
One day he visits a town near the castle.
It's tranquil and lovely, and the townspeople treat him with disregard.
What the...! He's worked his whole life for this!? Unbelievable.
A rage grows within the bitter man, a rage that he directs at the peaceful town.
He suddenly unleashes upon them all his frustrations.
Anyone will do! Rape 17 village girls!
Algis has discovered his inner evil. Beneath the hero mask...
He's a brutally merciless sex fiend with a black heart!
The adventure begins...

[From DLSite]