Since this doesn’t apply to one specific game in the Borderlands franchise, but all of them I figured I would out this here:
Exploring Atlas & Sirens
So, seeing how Atlas knew more about the Vaults than anyone else, I had a thought. Since Jack bought the rights to Atlas, lets assume his knowledge of Sirens came from that acquisition.
Atlas had one confirmed Siren of the six, Steele. Atlas also had Five Omega Assassins
And of course Athena.
They all share character models and attacks in BL1, but what if there was more to it?
What of Atlas had figured out a way to identify potential Sirens and selected these six women to train up for the time when their powers manifested.
Angel & Lilith’s emergence meant that there were two less siren slots, which would account for Athena’s or any other Omega Assassin’s lack of powers. Steele’s death could be the trigger for Maya’s powers emerging. Perhaps those with emergent siren powers were fitted with power inhibitors and that’s where Jack got the tech that he used on Angel & Lillith?