Sailor Moon Au - Dark Endymyon
Anyone can adopt this idea and adapt it!
Beryl killed princess Serenity in the hope of unleashing a war between the Earth and the Moon.
However, Helios discovers it and captures her, delivering her to Queen Selene to submit Berly to the Queen's judgment.
Prince Endymion disagrees, is angry and would like to kill Beryl himself for what she did.
Anger makes him a prey to the darkness, and it is he who invades the Silver Millennium to kill Beryl and obtain the Silver Crystal.
In this way, he believes he can bring his beloved back to life.
"You are weak, Queen Selene! You have the power, and you don't use it!"
"Do you think Serenity would want this?"
"She would want to live! She would want revenge!"
"Then, you didn't know her."
Queen Selene manages to seal Endymion and his army at the cost of her life.
Centuries later, the army of darkness and its prince awaken. The aim is to find the Silver Crystal.
Endymion's not-so-secret goal is to resurrect his princess.
(Usagi would like to hate him, but she has never seen anyone with such sad eyes.)