I just wrote this backstory for my Liberated Borg.
I personally think it's very good, even though the end is rushed a bit (but that's because it's 2 am here now).
Amanda Amans (prefers Calanthe)
Career: engineer
Age: 35
Current ship: U.S.S. Caennaire
Born to Starfleet parents, Calanthe had always lived on starships or starbases. However at the age of eight, the ship she was living on was attacked by the Borg. The U.S.S. Arcus Pluvius, a science ship, had been almost destroyed by the Borg before they boarded. The took the girl, named Amanda Amans back then, and assimilated her.
Five years later a single Borg cube was sent to Earth. For some reason this cube had been cut off from the collective and the drones had become individuals. When cooporation between the now individual drones failed and they did not succeed in rejoining the Collective, they became anxious and violent towards each other. Eventually factions arose and after a while the most violent factions were obliterated.
By this time the survivors had developed a self preservation instinct and managed to agree to a cease fire. Negotiations between the factions eventually led to one simple conclusion: everyone wanted to go home. Or what was their home before they got assimilated.
However, with over a hundred different species on this cube, going home wasn't as simply as it sounded. Aside from the fact that the homes of some of these species were completely obliterated by now, some species were in war with each other. The Klingons (all three survivors out of 238 Klingons of them) wanted to go Qo'nos, the Cardassians to Cardassia Prime and so on. Almost another war broke out on the cube.
However, most of the former drones had memories about the Federation. Not necessarily their own memories, but memories nonetheless. Almost all of them suggested that Starfleet was always willing to help. Starfleet would be the place where they had the biggest chance at survival. Starfleet was the place that would see everyone home or at least a safe place to live.
The one who brought this idea on the table was Two of Five, faction leader (they didn't bother with faction names; they knew who belonged to who's faction). A course was set for Earth.
The following message was sent to Starfleet Headquarters and every ship around Earth by the Borg cube (now surrounded by a dozen Starfleet ships):
‘We come in peace. We request permission to send three drones to the surface for negotiations. We expect an answer in one Earth-hour.’
One hour later an answer was received by the Borg:
‘One drone is permitted to beam down on the grounds of Starfleet Headquarters.’
The former drones agreed and Two of Five was beamed down. When she arrived, a total of fifteen Starfleet officers surrounded her, plus a few snipers on the roofs surrounding her. An admiral walked to Two of Five and welcomed her.
‘I have chosen the name of Calanthe for myself, but I was known as Amanda Amans before I was assimilated. I am here to negotiate the safe de-assimilation of every remaining drone on the cube and a safe return to our homes.’
The admiral, visibly surprised, welcomed these negotiations.
By the time the de-assimilation of the drones was complete, Calanthe had already joined Starfleet, not knowing what to do else now that everyone was safe.
Let me know what you think about it!
I am thinking of actually writing this story as a fanfic.