Heretic: Shadow of the Serpent Riders (1996)

In a twisted medieval dimension, undead creatures and bestial horrors have done the unthinkable--callously slaughtering your entire race. Your friends. Your family. Eliminated. But the nightmare has just begun. Wielding ungodly weapons such as the Firemace and Hellstaff and casting spells from the Tomes of Power, you must seek your vengeance. Or die trying.