I'm currently in the process of reading the best Seiya + Usagi/Serena (from Sailormoon) fanfic I've probably ever come across. It's called "The Heart of Cosmos", and it takes place after the last manga/season 5. I don't want to give any spoilers away, but this is a small illustration from chapter 13.
These two are really meant to be.
The fanfic is by SolarGuardianChick on fanfiction.net/, you can find the story here: [link]