They are not alone. They have the shadows with them and the other old friends they hadn't seen for so long.
Probable outcome; Imperium puts them in the same class as semi-dormant tomb worlds. Don't prod them, don't make eye contact and say off of their fucking lawn.
Same attitude the Naan had to the Old Ones at Sigma 957.
>>51150426
*heavy breathing*
http://www.starfleetjedi.net/forum/viewtopic.php?f=12&t=6409
"Megatons? Kilotons? Who-gives-a-ton?"
(The last one is the IoM and their GIGAtons of firepower.)
Vorlons/Shadows/Old Ones flee and if they learn a bit about the Tyranids. (Multi-galaxy, perhaps even 'most of galactic cluster'.)
Also they shit bricks. And if Bioships turn to Chaos, or Vorlons do... oh boy. (Shadows are shoe-ins for all the War and Khorne, but might go Tzeentch for knowledge. Vorlons go Tzeentch, definatly.)
Can you say 'Chaos Bioships'? Also smallish planet killers. Oh yes. That is the most 'fun' thing Chaos will get access to. No need for Old Ones bioship production, WH40k is good enough in this, and some Chaos Biologicsl expert can help. Also can a bioship creating station made of Warpflesh make real ships? (Yes they can if they use 'real' materials in the EoT.)
So galaxy is fucked, and the Old Ones are killed by the IoM to prevent Chaosification. Some flee, a few go to Chaos and the galaxy has 'FUN' times in it's future.)
>>51152561
>http://www.starfleetjedi.net/forum/viewtopic.php?f=12&t=6409
I would point out that none of this really deals with the capabilities of the First Ones, just the Centauri and those who were in technological contact with them. And it's far from clear that the Vorlons or the Shadows broke out their nastiest weapons in-show; that wasn't the point, after all.
>>51150426
They'd likely nope right out of there, and investigate a different Galaxy instead.
That one's about to fucking DIE.