He also plays a role in The Lost Tribe quest as one of the citizens of Lumbridge which you should speak to about the strange goings-on beneath Lumbridge Castle.
From his younger days, Father Aereck is friends with another priest named Father Urhney, who currently resides in the Lumbridge Swamp as a hermit. According to Urhney, Aereck always "gets himself into lots of problems", such as the instance when he "kept on getting stuck, up bell rope" when the two were priest initiates.
Aereck is the solution to the medium anagram clue: AREA CHEF TREK. The answer to his challenge scroll is 19.