User blog comment:RayShepp654/How to defeat the Reapers Theories/@comment-1221773-20101031021231/@comment-1221773-20101031045420

What I'm saying here and what I think will actually happen in ME3 are two entirely different wads of gum. Right now, we haven't got the slightest notion about how the Reapers will enter the galaxy. Will it be through a wormhole? A jury-rigged Citadel substitute? Will the Reapers enter the galaxy all at once? Or will only a few get through at a time? For the Reapers, the best situation is clearly that they can all enter the galaxy at the same time. I doubt this is what will happen, however, because what are the odds the final game in the ME trilogy will end in utter tragedy?

As for your second point, if in fact all of the Reapers are able to reach the Citadel, any defense force automatically becomes a non-issue. Boiling the equation down to "the Citadel's controls can only be manually accessed by a humanoid being", all the Reapers have to do is spawn a few husks/avatars, "assume direct control", and go get the job done.