User blog comment:Ralok/An Invitation to the Crucible Era/@comment-1596833-20120318050149/@comment-160529-20120320221831

The explanation given ingame is that when they traveled through the relays they found worlds or. . . readily accesible for colonoization. ..

it is a flimsy justification, but it is the one that mass effect provides.

Issue with the geth can be resolved in numerous ways, but i have yet to chose my solution to it.

Personally I believe the indoctrination theory, and that the catalyst lied about the geth to keep shepard from destroying the reapers. . . this is fan-wank territory though, and I feel like I am going to have to come up with a better explanation in time.

I am probably going to settle on control being the canon ending, since it is indicated to be the paragon ending of the series. . . if I settle on that ending, I have a plan for integrating the reapers in a unique way