Something I don't quite get about Gears of War.

[An Enemy Spy]

So what exactly is the Imulsion? Is it an intelligent life form trying to wipe out all other life on Sera, or just a mindless sea of biomatter that parasitically feeds on other cells?

[Blue Bandit]

I found a link that might help.

Warning, link contains possible spoilers
http://gearsofwar.wikia.com/wiki/Imulsion

A quote from the website "spoiler alert"

During the Lambent Pandemic, Adam Fenix determined that Imulsion was actually a living parasite feeding off other beings, including humans.