Borderlands 3: Siren Song

[Part of the Wasted Land story]

After some quick study, Tannis is fully sirened up and destroys the defenses to the Calypso's Cathedral and main base, letting the united Crimson Raiders attack the compound where Ava slays Troy, avenging Maya and absorbing his energy which activates her latent siren gene. Tannis takes her as her apprentice.

Unfortunately Troy had already begun unlocking "the Great Vault" having discovered that the moon was actually the key. Within was meant to be a universe destroying creature that his sister Tyreen wanted to absorb to cement her godhood - she was just running an errand on an Eridian homeworld to kill her father while waiting.

With that out of the way Tyreen warps back to Pandora only to find Lilith and Moze already waiting for her and is wiped out easily by the Mechwarrior. Alas the moon is now too close to Pandora and there's no stopping it anymore except through self sacrifice. Taking her siren powers back from Tyreen's corpse, Lilith becomes the Firehawk once more and uses her gift to fly up and then self detonate on the moon, pushing it away - resealing the Great Vault and saving Pandora.

Will we ever see her again? Probably because there's that Borderlands movie coming out.

Borderlands 3: The Sword and the Gunslinger

[Part of the Wasted Land story]

The next key pieces are on the planet Promethea, home of the Atlas corporation, but it too is under attack by both Maliwan and COV who are in clear alliance. Fortunately, Lilith knows of allies here as well, the first being Mad Moxxi who distracts most of the COV by participating and winning the galaxy wide broadcast of "Who wants to bang a bazillionaire" in nearby Lectra City, basically an all female city wide death match with the winner being able to bang the host in front of a large audience, both broadcast and live (with much audience participation to boot).

Lilith's second ally in the area is the space ninja (warframe?) Zer0 who makes use of the Sanctuary III to assault the Maliwan orbiting death star to end the war and earn the remaining key parts that Dr. Tannis needs to finish the key.  Maya volunteers herself to open said vault where she defeats the impressive guardian monster within only to then encounter the Calypso twins. While Tyreen absorbs the power of the defeated monster, Troy absorbs and disintegrates Maya herself.

While they replay her snuff film on a loop, Dr. Tannis discovers that this vault seems to be linked to another on Eden-6, the swampy home world of the Jakobs family who are also in conflict with the COV. They hire a trusty gunslinger squire named Clay - the lone merc who didn't simply take Calypso money and leave like a whore.

Borderlands 3: The Bluehairs

[Part of the Wasted Land story]

While the overweight mechanic Ellie repairs the Sanctuary III, mostly damaged by the idiot droid Claptrap, ship doctor and artifact specialist Dr. Tannis determines where the map is pointing to: a planet called Athenas. Luckily Lilith knows of an ally on that planet: her siren friend Maya who openly admits that they are guarding a piece of a vault key... and that they are under attack from Maliwan forces who are after the same thing!

Maya's also a cosplay favourite it seems.

Maya fights through the hi-tech Maliwan soldiers (the backpacks always seem to be their weak spot) to get to her idiot brat apprentice Ava who was busy not guarding a library as ordered and instead clearing a ratch infestation from the local brewery.

After a long and arduous climb (this is such a grindy and poorly designed level and is in an awkward place in the actual game) the blue haired pair then manage to reach the high temple, make heavy use cover to defeat the Maliwan raid leader and collect the key fragment before beaming up to Sanctuary.