The cohorts are up and running but we could use more members in them to be as effective as they could be. Each cohort specialize in a particular field or role for the legion. But if needed they will can be temporarily re tasked on a Legion priority operation.
to view the description of each cohort look at the ranks/ cohort page up top^. from their join the one you want to help out with. Being in a cohort is a great way to have fun with the other members of the legion.