Marrash is unusual for a Dragonborn in that at some point, he chose to follow the tenets of a religion, even though his understanding was skewed.
The teachings of Kord appealed to him. The idea that strength was to be honored above all else led Marrash to try and clean up Esterholt by brute force.
Marrash betrayed a contract by House Silverclaw and Group 3 was contracted to put a stop to his brutalizing of anyone breaking the law, including the town guard.
They did catch up to him soon after but to save their own lives, agreed to turn him over to Sariff, who represented SIlverclaw.
Marrash was taken away, and is assumed to have been executed for his betrayal.
A huge Dragonborn, almost as wide as he is tall and fierce in combat.