It is unknown what became of Moghbragga, but given that many of the Fallen Lords and allies of the Leveler were warriors and mages from the Wolf Age, it is quite plausible that Soulblighter himself resurrected or brought Moghbragga back to life using the same animating technique that he used for Shiver.
This is highly possible as the Oghres have a strong connection with the Mauls, and the Mauls openly serve Soulblighter, it would make since that they would follow him so devotedly due to their ancestor being resurrected and pledging loyalty to Soulblighter. This is of course speculation, but in the text it states that Soulblighter promised them new lands to conquer, and given Soulblighter's nature, the nature of the myth world, and the connection between Mauls and Oghres--it just makes sense for Moghbragga to be the leader of the Mauls--especially since he can wield dream magics as shown in Myth 3 the Wolf Age. Also, the Mauls are what were sent to destroy Myrdred in the Mission "The Deceiver" why would they be so adamant about killing him if Moghbragga wasn't their leader? It is stated in Myth 3 that Myrdred sent the Oghres to their deaths against the Trow, Moghbragga was the smartest and no doubt Soulblighter could have used this event in time to sway the Mauls and Moghbragga to his banner--making them all fanatically loyal to him.
Moghbragga could use the Binding Dream as the Deceiver taught him how to use the opposite on his people. Outside of this power, Moghbragga was the fiercest and greatest warrior of his race.