So I wrote up a concept for a Black Dragon a few days ago and was wondering if there were any known loopholes.
So, what I came across, was that there was a Black Dragon by the name of Serinar
that was housed in the Obsidian Dragonshire. He wasn't brutally hostile, seeming to be a more deceptive character (similar to Onyxia). He was not mentioned (or at least I couldn't find mention) during the Cataclysm. I assumed he was dead after Wrathion's speech about how he delt with the Black Dragons under Neltharion's reign. So, since there is little to no lore about Serinar, I wrote that he was fully aware of his corruption, and the last eggs in the Obsidian Dragonshire holding the embryos of black whelps would hatch sometime around the Fall of the Lich King. These whelps would be told to run and hide amongst the corners of Azeroth, sensing a growing fear which would later end as the Shattering.
So the character I wrote, cast himself far from Northrend, ending up in the caves near the Swamp of Sorrows and Blasted Lands. He housed himself there, feeding off the wildlife and harnessing his misunderstanding of his castaway as anger, trial and error of flight by the mountainous coastlines, and harnessing the fire of his belly to help feed himself. He stayed hidden until he was disturbed by the Iron Horde's invasion, where he was drawn out in the guise of a human enchanter. He then took this time as an excuse to finally discover what the world was truly like (roughly 9 years after his birth). He's generally reserved in his speech, and remains uncorrupted due to his lack of influence from any flights.
If anyone has criticism I'd be curious to know as well as the OP.