Marmaros

Rewards trader is a NPC involved with the skill Dungeoneering.

Apperance
The rewards trader appears to be a child or young man. He wears scruffy clothing and appears to be cowering behind a shield. While speaking, the rewards trader is frightened by the Adventurer and everything else around him. He is adept at mending and can mend items for the Adventurer.

Identity
The rewards trader might be Marmaros, as you can read in the "Marmaros and Thok" that Marmaros and Thok ventured into Daemonheim, which may have caused his fears. Also, Thok is standing right beside him.