Tolkien went with the most boring outcome possible for Elrond and Elros at the end of the First Age. Consider instead:
- King Elrond of the Sindar and his brother King Elros of the Edain
- King Elrond of the Noldor (if Gil-Galad is Ordoreth’s son, Earendil has a better claim)
- King Elrond of ALL the elves in Middle Earth, Noldor and Sindar
- Triple King Elros of the Sindar, Noldor, and Edain
- Elrond and Elros claiming they have a psychic bond, and therefore they’re both Triple-King
- No one knows what maia-human-elven twins grow up like, so no one can dispute it
- One of them going to Valinor and arguing that he should be king of Tirion instead of Finarfin
- Also trying to get counted as a prince of Aqualonde, because they’re Olwe’s nephews.
- One of them going sailing with their dad Earendil for a few centuries, hanging out in Valinor afterwards, comforting Grandma Melian as she waits for Thingol to be reborn
- Elrond saying “I don’t want to be a Man, but I won’t be an Elf either. I choose to be a Maia, like Melian.”
- I have no idea what happens when there’s suddenly another one of the beings that existed as long as creation, but I bet he shakes things up.
- Elrond becoming herald of Ulmo and herald of Yavanna, then lording it over Eonwe
- Probably results in Elrond fighting Sauron in hand-to-hand combat and winning
- Just checked, and they were allowed to ‘choose freely to which kindred their fates shall be joined.’ No mention made of blood ties.
- I’m saying Dwarf!Elros and Maia!Elrond
- And Elros somehow ends up king of the dwarves, possibly by flaunting his adoptive descent from Feanor, the greatest craftsman in history