User blog comment:TheUnknown285/A very interesting image from the remake of Halo (yes, this is ME-related)/@comment-2250460-20120401033857/@comment-3228423-20120401042200

It's simple, Forerunner ships are at least 7 times the size of the big Reapers and one of them has the firepower to stand up against an entire Sangheili fleet. That and they use laser and plasma weaponry, something that the Reapers can't exactly defend against. And the Flood pretty much use the ships they stole from the Forerunners