Mission 10

This is the first mission where you must face and defeat an elite Overlord. To draw the Overlord out of hiding destroy the spawners and then the Gate. However, you should also quickly destroy the trap generators or they will make the level very difficult.

The elite Overlord (as shown by his purple health bar), is much tougher than a normal Overlord. The best way to deal damage to him is during Blue mode. You will deal double damage to him in this mode. Also, the bluetonium, if you don't immediately collect it, can greatly harm the Overlord during Blue mode - especially if you have energy manipulation.

There is no shame in going back and farming some research points or looking for secrets if you are having trouble.