The more I read new snippets of info as it's being released by BL in books, the more I get convinced that the "Fallen" were loyalists and the Lion and those DA's in the crusade become corupted and wanted to turn renegade.
The war on Caliban stopped that and the remaining DA's saw the error of they're ways and hidden the truth and now hunt the fallen to prevent it from ever being found out.
Who knows what happent to Jonson in his first years on the demon infested forests of Caliban......