initial sketch was done just after i finished my first playthrough and just never got to finish it.. but this is something that every doctor who fan who played mass effect 3 thought of in one way or another XD
A. The doctor survived that and is enraged (not just angry, enraged) and will stop the reavers. (Will probably use the daleks to do that, since they also have the destroy everything shtick and don't want company on their turf)
B. The doctor didn't survive. That would mean the reapers are the least of your problems.