What if flood started as an visur on another galaxy?
Yes like the T and G-virus at resident eavil?
And then evolved and could take ower body and become its host, then it broke free and started killing things, and when 1 galaxy was destroyed that it moved a small force to another galaxy.
Our galaxy, the milkyway, and when it landed on G617 it stayed dormant there till forerunners discowered it.
Well this theory is dumped into trash if Timelessone is teling the truth and precursors created the flood, but on the other hand we dont know ewerything about halo lore, and might aswell flood started as virus, landed on milkyway, precursors found it, refined it and created their ownt type of flood.
But it is just an idea hitting my mind out for 30secs... So dont flame on me...please.