User blog comment:James12708/Reapers VS. Forerunners VS. Angels from Darksiders VS. Humanity from Halo VS. Council and humanity from Mass Effect VS. Imperium of Man/@comment-50.80.96.33-20130111063144/@comment-2250460-20130111064524

Lets list the problems with that:


 * Collectors take a while to Harvest Colonies, they could be dealt with before they fully collected, not to mention colonial militias.


 * The Flood were not mentioned as being in this war (neither where the Collectors for that matter), so you can't just assume they are part of it.


 * Even in a severely weakened state, they Imperium of Man and the Forerunner empire would still utterly curbstomp the Reapers.


 * Lets not beat around the bush, the this is a war between the Imperium of Man and the Forerunners, everyone else is just irrelevant. The only thing that gives the Reapers an edge is the trump card that is Indoctrination.