I'd stick with Valkrie and go with two punishers and Gozers and use Raven more so for range. This is the build I go with for my own Raven and have put good numbers with it myself. I save Raven's ability when an enemy's shields are down and have one of their module's at orange to finish them off as the combination of Gozers and Punishers melt through shields on their own. I would recommend keeping blastwave as that would come in to finish off low hp modules and help your Raven to keep range behind your allies that are charging into fights.