Aerodus was born to a somewhat wealthy family in Egorian, the capital of Cheliax. His family worshipped Asmodeus, and as Aerodus had a link to the Infernal Plane (something his father was VERY proud of indeed), they teached him the Dark Prince's ways fervently. So it was, that when Aerodus got older he joined the clergy.
Aerodus's father once bought him a halfling child as a slave, but the brat escaped. As punishment, Aerodus was ordered to kill the halfling's parents. Aerodus found that he very much enjoyed the thrill of the kill; something that would help him greatly in his service to his dark god.
One day, Aerodus heard of a chance to serve Cheliax by joining with the Pathfinders. While not everyone in the Pathfinders liked Cheliax or Asmodeus, Aerodus figured he could get in some kills and make a name fo himself, and for the Dark Prince and wasted no time in joining.