I’m not as well-versed in Flood lore as I’d like to be, but everyone’s saying the Flood can’t survive off of microorganisms which means they’d be screwed against the Vex. The Flood’s infectious abilities have been shown to be more intense and bizarre than those of the Vex, but the Vex have very similar infectious abilities. On top of that, the Vex have shown to be so infectious and resistant to infection that they can even counter being Taken. The Vex even compartmentalize their Minds so that no infection can spread through the Collective. All it takes is any contact with Vex radiolaria or mind elements and organics and machines can be infected. On top of the advantages of their microorganism+machine bodies, the Vex are also so capable with information and simulation that they can predict everything the Flood will do. If anything can discover a way to stop the Flood, it’s the Vex. [spoiler]And Oryx could probably single-handedly defeat the Flood due to his sheer paracausal power and the ability to Take.[/spoiler]

I love how often the Vex vs Flood debate comes up. Honestly I’d love to see how a war of that scale would go down, especially considering how identical their abilities are It’s a hard call, but I expect that the Vex would win. Yes, the Flood spread very rapidly and can likely take over the Vex radiolaria that composes their collective consciousness because it is organic, but the Vex have demonstrated much more impressive feats relating to infection. They’re not limited to organic matter, for starters, and have also been proven to be able to win out against Taking, which is a big step up from Flood infection when it comes to resisting or countering the effects so shows that the Vex would likely be able to find a way to overcome Flood infection as well (plus the Taken are supposedly not even composed of solid matter anymore, which again says a lot about the Vex’s abilities). The Vex infectious cells also convert the consciousness and even AI minds, which again is a step up from the Flood’s Logic Plague and means the Vex might be able to disrupt Hive Minds so that the Flood can’t come up with intelligent strategies to fight back. And on top of all that the Vex are masters of planning and construction and can build things to slow and contain the Flood without even having to risk themselves much. Starving the Flood out probably wouldn’t be too hard for the Vex as a long term plan So in the end I believe it comes down to their infectious power since their military might is seemingly equal (excluding the Vex’s far superior means of transportation and slightly superior information network), and the Vex simply seem to have the edge there

[quote]I’d be very interested in this fight. But for the love of god no one say logic plague, the vex are not robots they are microorganism within metal bodies. But it would be interesting as the vex have no nervous system and radiolaria can infect and convert organic beings into vex (Kabr and Asher Mir) when touched much like the flood. Also I would assume the vex minds are much more intelligent than Forerunner AI like mendicant bias as they have many minds the size of planets and can simulate the flood in order to create strategies as well as predict what they will do.[/quote] the thing with that is the flood can also infect AI(or whatever the Vex are) and once they do that the vex are just goners