The identity of Sailor Cosmos remains one of Sailor Moon's biggest mysteries, but there are some clues about who she really is in the manga.

ruling as Neo-Queen Serenity. With Sailor Moon's incredible power capable of stopping even cosmic-level threats in their tracks, she's certainly a well-known historical figure in her own world ...

This would also give us a chance to see how Sailor Moon’s powers change when she’s Neo Queen Serenity, and how that affects the way she rules. After all, it had to take time to turn the Tokyo ...