Okay, allow me explain the "cult" scene.
As the 2FL said, "I am only a mouthpiece". It hints that she exists because it humanity has been secretly desiring to see who slept with whom.
Later, she also said that her existence was exactly to bring in the S-Day, and after that it doesn't matter if she dies or live.
The "cult" is the representation of her power. She gains power because there are people being controlled by the S-glasses. The secret desire of those people is giving her power.
This is a common trope even in European mythologies. The trope goes that the g-ds exist and have power because humanity secretly desired to have g-ds. The more a g-d is worshipped, the more powerful that g-d becomes.
In Neil Gaiman's "American Gods", he deeply explored this ancient trope and adapted it into the modern world. In his story, there is a g-d of handyphone. The more people use it and are glued to it, the mire powerful he becomes. And the many, not all, of the old gods are weaker, dying, or getting murdered because they no longer have worshippers and thus almost powerless, not even to protect themselves.
In Neil Gaiman's "Sandman", that same ancient trope was used again. You can watch, I think it was in S01, the episode where a goddess died because she's so weak. She had few temples left and few worshippers. Guess what her temples are? R-21 adult bars. Who were her worshippers? Patrons of those bars.
Even in Greek, Roman, Egyptian, and Nordic mythologies, this trope was touched on, and sometimes used to weaken another g-d.
Going back, that is what that "cult" is about, and potentially that is what the 2FL's identity is. She is a goddess made out of human desires and to power up she need constant worshippers.
Noticed how she tried to lure the detective? Because the detective did not fall under her control. Meaning, the human wearing the S-glasses should unleash their inner desire to murder, to accuse. But the detective remained objective and in full control of himself.
Later, after she died, she appeared as a spirit to the 1FL. It's a hind that the reaction of humanity during the 1 year time jump, enabled her to exist as a spirit, and started following the 1FL. Now, she truly is a goddess, no longer one trapped in a shell that dies.
I hope that helped.