Not to be confused by the character, See Nexolord (Character)
The Nexolord is the strongest tamer of all tamers and nexomons. After defeating Omnicron, Ulzar became the first Nexolord, there is no record of the following Nexolord until Ex-Nexolord Remus who was defeated by "The Nexolord". You can read more about the Nexolord's duties and responsibilities in the Nexomon-Human War.