tension among the xiliens' ranks soon rose, however. while the leader of the xiliens wanted to take over the planet through as peaceful means as possible, the second-in-command believed in their superior firepower and technology, and wanted to return the monsters to earth. it was soon discovered that the xiliens were replacing high political leaders with xilien clones, and that gorath did not actually exist. the xiliens were exposed on national television, and with their plan revealed, the second-in-command (henceforth known as the controller) shot and killed the leader, taking command of the invasion from that point on. he explained that the reason for their invasion was to use mankind as a food source – the xiliens needed mankind's mitochondria to survive. upon returning to the mother ship, he returned the monsters to earth, and this time they were assisted by swarms of xilien fighters. he also activated the xiliens' ancient weapon – a cyborg kaiju named gigan.