If Void is quick to anger, I imagine Nabondius to be more level-headed and more suited to seeing the 'big-picture'. If he wants to control the Dreamkeeper World, he'd have control over himself first. If Void is a sledgehammer, Nabondius is a scalpel, Void is blistering heat, Nabondius is chilling cold. He likely rarely raises his voice and is (rightly) convinced of his ability to make the smart choice in a situation instead of other Nightmares.