By reactivating the Vex portal built by Clovis Bray, Eramis endangered all life on Europa, including her own soldiers' lives. Though you successfully thinned the Vex hordes, Eramis was still able to collect the radiolarian fluid she needed and escape.
What she plans to do with this resource is not yet clear. What is clear is that the Darkness has fueled her anger into a reckless rage. She must be stopped once and for all. The time has come to complete your journey with Stasis.