By a stroke of fortune Grand Duke Mhoram, the neutral High Priest noticed this scruffy boy with the orcish sounding(?) name. He also noticed that there might be potential behind the dirty surface, so he took himself time to speak at length with this mortal boy.
As a result of the long (mostly one sided) conversation Gorb agreed to move in with the Grand duke to learn about the ways of neutrality. After getting some food and clean (civilized) clothes for his guest Mhoram started to teach the boy some manners.
As time passed the Grand Duke showed Gorb the path to enlightenment, and even vent as far as introducing him to the neutral god Reset. When the Grand Duke saw that he had not made a misstake he offered to take up Gorb as his apprentice in the arts of magic. After considering the question a while (He had allready calmed down a bit and did no longer make decisions without stop to think first) Gorb agreed to take the position.
In a gesture of his devotion to Reset - god of all DUMdom, and the start of his new life, Gorb had his name changed to Rorthron. Rorthron soon noticed that Mhoram was a harsh teacher that did not allow any misstakes. The pecky old man with his notebook (where he made notes of all Rorthrons errors) and his lightningfast strokes with his staff whenever Rorthron made an error or said something more stupid than usual, was quite different from the gentle old man who had been sitting talking at length with him over some warm spicy vine.
Eventually the Grand Dukes efforts gave effect and Rorthron began to be able to use his magic powers in the way they were meant to. When Reset in his wisdom saw that Rorthron was ready and gave him the quest for immortality Rorthron immediatly set out to fulfil the gods quest. The Grand Dukes training had been hard, but had prepared Rorthron very well for this final test, so before long Rorthron lay aside his mortal self and let the pure power of his magic blend with the air of the world.
Rorthrons master had been awaiting this moment, and before long Rorthron found himself take care of more and more of the churchly matters while Mhoram could spend more time relaxing and doing all kinds of strange experiments in his laboratory. When this seemed to work out well, Mhoram promoted Rorthron to Priest of neutrality, so that he could spend even more time siiting in his comfortable chair reading books while sipping some nice wine from Gondor.
50 or so years later Mhoram decided that Rorthron was quite capable of taking care of things himself, and decided to step back from the position as neutral High Priest. Reset didn't show any surprice as he agreed to his High Priests wish to step down from his position and installing Rorthron instead.
Ever since that moment, through millennia Rorthron has held the office as neutral High Priest, battling both good and evil, depending on the needs of balance. During all this time he have had strong support of a childhood friend, a firedeamon nowadays known as Marg - the Firelord.