The Tomb of the Grave Knight

From the description: In ancient times, the land was ruled by an evil king named Zagren the Ruthless. When he was eventually overthrown, he was buried with his closest allies in a tomb built to hold his rage forever. Over the centuries, tales of his brutality faded into myth, and became nothing more than ghost stories to tell misbehaving children. He would have been lost to the annals of history had it not been for his overwhelming and deep seated anger. That rage corrupted his soul and those of his allies turning them into undead horrors. Now, the undead king stirs in his tomb. His knights roam the land raising the dead as soldiers and preying on the living wherever they might meet. Unless someone defeats Zagren once and for all, darkness will consume the land.