Multiverse War
Millions of years ago, the First Multi-verse War plagued the first sentient life of the Milky Way Galaxy and its neighbours. As intelligence evolved to the point of ascension, so too did warfare and alliances progress from those between city-states to those between galaxies and parallel universes. The war was finally won, but at a terrible cost. Unable to finish off the enemy, the Allies banished their enemies to another galaxy. Their societies and ways of life decimated, the Allies were almost completely annihilated by the unforeseen consequences of their victory. Member species rebelled, new enemies were made, synthetic life forms went rampant, and synthetic/biological experiments came back to bite them. Across multiple parallel universes of the Alliance, what few were left did their best to contain their mistakes and then ascended to a higher plane of existence. Now, millions of years later, their enemies have re-established their empires and set out for revenge. They have significantly weakened the our galaxy by manipulating interstellar relations and warfare. Attempts to completely annihilate the Allies' descendants have failed, however, meaning that invasion is coming soon, while everyone is weak. Guided by the Ascendants, a new generation of multi-verses will have to unite against a common foe. But, will this new alliance, led by the humans of the United Nations Space Command, Stargate Command, Starfleet, Interstellar Alliance, Citadel Council and their allies be enough to stop the new onslaught?