The Dark Heart of Uukrul

You four - a warrior, a magician, a priest and a paladin - you tiny band of four must somehow vanquish the evil Uukrul. For he and his depraved followers hold the once-lovely city of Eriosthé in dark dominion. And until he is destroyed, the entire land lies helplessly at his mercy.

Note: it uses DOSBOX but GOG officially package it for Linux.