He replaced the wizard Hannicus as master of the Yellowstone Mines and promptly introduced sweeping changes that impressed Marr a great deal. To begin with, he ceased paying the workers and began an effective system of replacing worn-out workers with disgraced soldiers or slaves to ensure constant production.
Darramouss then began to introduce a number of dark creatures to Marr's dungeons, making it extremely difficult for any to infiltrate them - as had been the case under Hannicus and the reason for his dismissal. Among these were Devourers and Clawbeasts, though it is suspected that he also put into place a large number of magical traps, given his extraordinary aptitude for dark magic. One certainty is that he can investigate the dungeons without leaving his quarters, through the use of a magical orb - perhaps with a spirit of some sort imprisoned in it, given that an ethereal face manifests within it when the orb is warning someone off or defending itself by expelling fireballs from the 'eyes'.
He is an unnerving individual who enjoys pointless torture and is able to maintain control over his beasts by thought alone. Furthermore, his hold on unlife is potent enough to keep him from being killed by normal means, making him utterly fearless even in the face of what to most would be extreme personal danger. At no time was this more evident than during the Trolltooth Wars, when at one point his cart was surrounded by the Chaotics of Balthus Dire and his sole reaction was to hiss, thus commanding his until-then-docile monsters to massacre his aggressors.