Kergak Slamslicer is a foot soldier of the Souballo Empire and was a member of one of Umbria's battalions before she was relieved of command. He is the only surviving member of that battalion, and Umbria let him join the group due to impressing her in combat.
Kergak joined the Empire for the food, camaraderie, to get away from an arranged marriage, and chance to become stronger. Though he is part of the Souballo Empire, he shows no ill will toward Elves or many others who are his foes...except giants.
Kergak is friendly and understanding enough, with a strong desire to please those around him. His dedication is sometimes ribbed by Umbria, but she seems to trust him and enjoy his company the most of her other teammates.
During their adventures getting to Silverfronds, Kergak's team teleported to an encampment that got slaughtered. There he found a shield which he seems to have an unhealthy attachment to.
The shield turned out to be possessed by a Dolormagister, a Neutral Evil Lands of Sadness Denizen who wanted to sell its services to Mortaridar.
The Dolormagister was destroyed before it even had the chance to speak to Mortaridar by a stray blast of destructive energy. So much for that monster and plot thread.