Lilith, the commander of the Crimson Raiders, spends the entirety of Borderlands 3 powerless and sequestered on the Sanctuary III giving commands to the vault hunters. The end of the game is may be interpreted as a finale for Lilith, but then again, it could very well be hinting at a DLC campaign for one of the OG characters from Borderlands.
Lilith begins Borderlands 3 more powerful than she's ever been. Throughout the series her power has been steadily increasing, both as a Siren and as a leader. When Tyreen and her brother Troy steal Lilith's power in the opening hours of Borderlands 3, it throws her entire identity into question.
Lilith then spends the rest of the game holed up on the ship giving orders from a distance. She refuses to face the Calypso twins head on, knowing that how powerful they are now that they have her power.
That isn't the only thing holding Lilith back though. Without her powers, Lilith scarcely knows who she is anymore. The Firehawk that ran head long into battle is no more, now Lilith is too afraid to get into another fight and lose.
Even when the Calypso's kill Maya and take her powers, Lilith is still too afraid to act, despite Ava's protests. It isn't until Tannis is captured and recovered (in one of the highlight sequences of the game that unmistakable stars magicians Penn & Teller) that Lilith finds the courage to fight back.
After defeating Troy and killing Tyreen the destroyer, Pandora is still on the brink of total destruction from the events set in motion the Calypsos. Lilith, with her powers now restored, tells Ava that Sanctuary is now hers, and echos back the sentiment that inspired her face down whatever comes next "Run towards the fire."
Lilith ultimately sacrifices herself to save Pandora, and as the credits roll (and Alicia Keyes' Girl On Fire plays) you may be left believing that Lilith's story is complete. Examine the evidence, however, and it seems likely that Lilith will be back sooner rather than later.
As she take's of, Tannis plants a bit of doubt: "That could kill her!" she cries out. "Could" kill her she says, not "will". Furthermore, consider the most important rule of story telling: any one who dies off-screen isn't really dead.
We saw Maya die right in front of us, there's no doubt that she's really gone, but Lilith, all we saw was a distant pulse of light and a Firehawk symbol on the moon. A Lilith dlc could be in the works. Lilith deserves one last hurrah at peak power, don't you agree?