Based on the erotic game by Alice Soft.

While Rance might well be one of the best swordsmen in the world, he has the personality of a rancid turd. He is narcissistic, lecherous, abusive and almost without any redeeming social graces. And his underclad and overabused slavegirl Sill knows this, but she is still in love with him. One day Rance is hired to defend a dusty and forsaken desert village from the repeated attacks of scantly clad and oversexed sorceress intent on the resurrection of a long forgotten deamon.

(Source: AniDB)