Clone Drone in the Danger Zone

This can be easily unlocked on the third chapter. The upgrade will be available for you at the start of the chapter. The first room that you enter will have 6 or 8 enemies (depending on difficulty) that can be easily grinded out after you have kill your ai teammate beforehand. (P.S. Make sure that you don't kill everyone in the room, you can be killed and will be able to restart at the last checkpoint, which is near the same room.)Also press the button to use the Flame Breath ability.