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-50.80.96.33-20130124014617/@comment-3228423-20130124034649

Well even if the Gravemind can't get into their computer systems (no idea how it did that when it tortured Cortana), the Flood can always get into a Reaper by either smashing their way in or finding the entrance and sabotage them from the inside.

Well that or just FTL right into them.