Rauric

The first Nighon Lord whom Mutare killed to usurp his lands.

Lost Lore 

An excerpt from Mutare's biography on the official (now-defunct) 3DO website:

...Using every last ounce of determination and will power, Mutare moved through the ranks quickly. Soon she was a general under a Dungeon Overlord named Rauric, but resented his control over her. For Mutare it was imperative no one else ever control her destiny. She coveted the position of Dungeon Overlord. All she needed was the opportunity to replace her condescending and insulting master.

He provided such an opportunity. During a large feast, after a few glasses of strong beer, he implied a woman’s worth lie in her physical appearance. Foolishly he had been looking Mutare’s way. Insulted, she jumped to her feet and challenged the Overlord. Thinking the young hothead wasn’t serious, the Overlord laughed and accepted the challenge. He playfully dueled with Mutare, then with a quick flash of her blade, Mutare beheaded the Overlord. No one challenged her authority as she seized the reigns of power.