Alpha Vek are significantly tougher; focus fire on them or use environmental kills. Horizon Psions are the highest priority target on any map they appear on; their shield ability makes all Vek immune to the first instance of damage, effectively doubling their health. You MUST eliminate the Horizon Psion immediately, even if it means sacrificing a Power Grid point. Use multi-hit attacks or environmental damage to bypass shields if you can't kill the Psion.
