Basically just juice up the orb cus it outputs crazy damage from a crazy distance. Use the beam early and often to create even more space. Sidle up just barely outta range of those towers and let the beam cleanse all. The level 20 archon buff provides unlimited laser so burn all your spells and stay just outta range of the base and melt it into oblivion. I could bore you with other small details but I recommend you just play back, launch orbs and practice up with the laser for snatching those runners.