You know what, I'll throw my hat into this since I have two idea for it.

[quote]1. Extra dimensional, formerly immortal beings who lived in a timeless, abstract dimension of hypergeometry. When the two galaxies crashed into one another, it caused something to happen in their dimension, a disastrous breach into their dimension, possibly from some long lost secret research project of a lost empire, spread something entirely unnatural to them: time. After untold thousands of cycles, the breach only continues to grow and infect their dimension forcing them to enter into our dimension and the Andaluzia galaxy because of:

	A) They are only a portion of their race desperately hoping to try and find a "cure" in this dimension to save their own 
	B) They are the last survivors of their dimension, forced to flee into this dimension or suffer a "true" death[/quote]

[quote]2: A terrifying race of living weapons, their monstrous existence once justified by the massive wars they were made to fight in. Their names are infamous and feared as stories and myths of the carnage, terror and bloody destruction they caused as they consumed worlds in fire and gore. Once they were thought to have all died out, along side with whatever force originally created them and remembered only in legends and ancient history. But they have returned, nightmares made reality once more. However this time, something is off about them. They are still monstrous killing machines bread for a terror war, yet they don't act like it, or at least they try to. For whatever reason, this last group of living weapons is trying to find some kind of redemption, perhaps as an apology for what their kind once did, or maybe for their very existence.[/quote]

Basically, imagine the first one being driven by desperation and panic. They're strong by their extra-dimensional nature but they're also very confused. One idea I had is that they have some ability in manipulating temporal flow, a hold over from their once timeless realm, but I honestly don't expect that to make the cut. The second is your typical forgotten living weapon with a society built entirely for war but they're trying to redeem or change their ways. Could be interest to see them fighting their very nature monster-within-style (dramatic I know) or what they would be like if they were forced into dipping back into the savagery that made their species so infamous to begin with because of some major conflict.

Edit: Will there be other or more specializations?