i would initially think this would be a close battle considering the flood, forerunners, precursors against force users and stuff like the star forge but then i remembered [url=http://www.youtube.com/watch?v=RW_hGOFukMQ]this[/url] i think with the blatant disregard for life that many of the halo factions have, this would prove an effective strategy (a single flood ship crashes into a star destroyer and everyone on board is potentially screwed)