Enemies of the Dragonmarked Houses – Wayne

Billy Rigby asks:

Dragonmark Houses are powerful, the 12 have a foothold on Khorvaire but who is against them? Who’s the enemy of the 12? It seems like they have no overall threat against them other than each other and other businesses. Do they have an enemy or is it a House by House basis? Is anyone trying to end the Houses and if so, why?

Wayne offers his ideas and suggestions.