The United Empire of Iridium Star in the Galaxy of the First Universe may not be the strongest or most advanced civilization, but at its level of civilization, it is definitely one with the most terrifying potential for war.
In some ways, Iridium Star and Teizene are quite similar. Teizene is a civilization oriented towards military aggression, whereas Iridium Star is a civilization geared towards comprehensive expansion. Both civilizations have a strong drive to expand outward. Teizene embodies brutal and ruthless militarism, while Iridium Star wields its mighty fists on somewhat reasonable grounds.
After the introduction of Atomic Substance Construction, the ultimate technology in productivity, Iridium Star's war potential had become extremely fearsome.