Ruthless, intelligent critiques only, please. 
The story arc will mostly center around Usagi having a son from the first Silver Millennium that she remembers nothing about. It'll turn out that he's the one responsible for the cycle of resurrection that keeps bringing her back to life, and that he keeps bringing her and her companions back to life (and killing them) for an unknown purpose.
It'll turn out that the planet Saturn is really a giant black cube space ship with infinite volume inside that in the Silver Millennium served as the prison for all the universe's castoffs, especially from among the nobility.
The First Mother - A young girl, trapped in a pocket dimension that allows her telepathic contact with all life in the universe. At the beginning of time, her father was displeased with the primitive nature of life in the universe and went to all of his daughters, one after the other, asking if they would be willing to serve as the First Mother. All of them refused except his youngest. The elites of Saturn learn of Her as the last step in their education, which is designed to remove any trace of compassion from them. KXI still retained some humanity, and was outraged at learning of Her imprisonment. And so She made contact with him, and him specifically, and they have been plotting to free Her ever since. She nurtures him and gives him purpose, and he gives Her a sense of form and individuality.
Hyperion - Usagi's brother. Was brilliant and powerful and owned a powerful gem that gives its user near-infinite power. At one point, Kronos duels her brother and mortally wounds him. Hyperion goes into a golden sarcophagus reserved for members of their family, taking the gem with him. Nobody but him, a sibling, parent, or descendant, can open it from outside, so Kronos can't, but Usagi can. And if somebody opens this coffin early, it will kill him.
I'll rewrite the way Endymion and Usagi died. Basically, before the giant battle with Queen Beryl, Usagi and Endymion went to Kronos XI, not knowing that he's their son, and beg him to use Saturn's weapons to kill everybody at the site of the battle, enemy and ally alike, if either of them dies, and of course he agrees to this joyfully. Afterwards, Queen Serenity begs KXI to resurrect Usagi and co, and he tells her that this would require a mother's sacrifice. From that point on, he resurrects Usagi and Co, hoping that they can be tricked into opening Hyperion's coffin so that he can lay his hands on the gem. Every time he has done it so far, he has failed, as Usagi always at some point remembered that she wasn't supposed to open the coffin, forcing Kronos to kill her and her companions and try again.
There will be a lot of places where it's obvious that he has issues, he'll get a sad look in his eyes where he looks down and to the left. At one point, he'll have this expression when he's on a subway and there's a mother playing with her baby. Another time will be when Usagi hugs him from behind, saying that it just "feels natural".
The story arc will mostly center around Usagi having a son from the first Silver Millennium that she remembers nothing about. It'll turn out that he's the one responsible for the cycle of resurrection that keeps bringing her back to life, and that he keeps bringing her and her companions back to life (and killing them) for an unknown purpose.
WORLDBUILDING
It'll turn out that the planet Saturn is really a giant black cube space ship with infinite volume inside that in the Silver Millennium served as the prison for all the universe's castoffs, especially from among the nobility.
CHARACTERS
Kronos XI - Because Usagi and Endymion's marriage was an illicit one, their son was taken from them by the enforcers of Saturn and raised by the rulers of Saturn, eventually succeeding them and adopting the name Kronos the Eleventh, as each ruler dubs himself Kronos the Nth. In the Silver Millennium, he was immensely powerful and feared, and has only grown stronger over time. He has massive mommy issues, which we'll get to.
The First Mother - A young girl, trapped in a pocket dimension that allows her telepathic contact with all life in the universe. At the beginning of time, her father was displeased with the primitive nature of life in the universe and went to all of his daughters, one after the other, asking if they would be willing to serve as the First Mother. All of them refused except his youngest. The elites of Saturn learn of Her as the last step in their education, which is designed to remove any trace of compassion from them. KXI still retained some humanity, and was outraged at learning of Her imprisonment. And so She made contact with him, and him specifically, and they have been plotting to free Her ever since. She nurtures him and gives him purpose, and he gives Her a sense of form and individuality.
Hyperion - Usagi's brother. Was brilliant and powerful and owned a powerful gem that gives its user near-infinite power. At one point, Kronos duels her brother and mortally wounds him. Hyperion goes into a golden sarcophagus reserved for members of their family, taking the gem with him. Nobody but him, a sibling, parent, or descendant, can open it from outside, so Kronos can't, but Usagi can. And if somebody opens this coffin early, it will kill him.
BACKSTORY
I'll rewrite the way Endymion and Usagi died. Basically, before the giant battle with Queen Beryl, Usagi and Endymion went to Kronos XI, not knowing that he's their son, and beg him to use Saturn's weapons to kill everybody at the site of the battle, enemy and ally alike, if either of them dies, and of course he agrees to this joyfully. Afterwards, Queen Serenity begs KXI to resurrect Usagi and co, and he tells her that this would require a mother's sacrifice. From that point on, he resurrects Usagi and Co, hoping that they can be tricked into opening Hyperion's coffin so that he can lay his hands on the gem. Every time he has done it so far, he has failed, as Usagi always at some point remembered that she wasn't supposed to open the coffin, forcing Kronos to kill her and her companions and try again.
PRESENT DAY, PRESENT TIME, HAHA
Kronos will enter into Usagi's life as an exchange student. The first definite sign that he's a lot more than he seems will come at their first dinner together. Usagi's mom will talk about how the cups she just bought are all shatterproof, they're basically impossible to crush, there was a commercial where they used a hydraulic press and everything. She'll talk, seemingly for the first time, about how she originally planned to be a pop star, but then married Usagi's father instead. She'll look a bit sad and wistful, and Kronos will crush his cup out of rage. Then he'll clean everything up himself and excuse himself.
There will be a lot of places where it's obvious that he has issues, he'll get a sad look in his eyes where he looks down and to the left. At one point, he'll have this expression when he's on a subway and there's a mother playing with her baby. Another time will be when Usagi hugs him from behind, saying that it just "feels natural".
ENDGAME
Basically, Kronos wants to free the First Mother using a multi-step plan.
- Using a device, he grants wishes to people that he considers to be overwhelmingly sympathetic to him. People who've lost their children, a bullied child who wishes his favorite superhero was real, etc. "Saints". This device also collects their visions of a better world, since he is too cynical and cruel to entertain such things
- He gets Usagi to open Hyperion's chest. He hopes that this time, things will be different, as this age is, in his estimation, laden with enough distraction and misdirection to keep her from figuring out his plan.
- He takes Hyperion's gem, uses it to power the giant black spaceship at the center of Saturn and go between dimensions and rescue the First Mother
- He takes the wish device and places it where the First Mother used to be trapped, causing it to absorb all the contradictory wishes, creating rifts in spacetime that will hopefully destroy the universe
- He and the First Mother remake the universe according to the program set out by the "saints" and according to their whim.
