Okasare Yuusha IV ~Mou Dame. Boku no Ochinchin wa Genkai na no ni~

A world under invasion by monster girls. You vow to liberate the people from fear, but the endless monsters and the demon lord are too powerful for a mere human. In your travels you meet a succubus who can help you gain strength and recruit monsters girls to the side of good. Of course, you can still fail... and if you do... A hell of creative, sexy enemies are waiting to reverse r*pe you!! [Slightly edited from DLsite English]