Herald is the name given to servants of Unicron or Shokaract. Those are usually Cybertronians who have pledged their loyalty to him or else been corrupted by his dark influence.
Herald Maximo is the title held by the highest ranking Herald of Shokaract from the future in which he ruled over Cybertron. The office was held by Antagony and sought after by Cataclysm during their rivalry and after her ill-fated trip to prehistoric Earth. Reaching the Omega Point
Note:It is unknown whether Shokaract gave this same title to his second-in-command in the Fun Publications comics, or whether it could be considered the equivalent of the "Champion of Unicron" title held by Nemesis Prime.