I'd heard of the name "Abbadon" a few times, but I bailed out of Supernatural after Season 6, so I never made it far enough for it to come up! But that's where pixiebelle heard it, too.

Which is exactly what it is! On a much larger scale.
It totally is-- on BOTH sides! Which was why I had to write it. How could I let an opportunity like that slip away?