9. Mera - Emilia Clarke
It seems that Mera might not be played by the same actor in the eventual, inevitable Aquaman sequel.
Thankfully, Jason Momoa was on this little independent show called Game of Thrones. On that show, Momoa's character's romantic partner was played by Emilia Clarke.
Though that on-screen relationship may not have been as romantic as just suggested, that experience - along with the great friendship the two have developed off-screen - could mean a whole lot. Having Clarke play a love interest more on the same level as Momoa's character would give audiences a duo with great, natural chemistry to enjoy.
Furthermore, that same Game of Thrones role also gave Clarke a fair amount of experience at portraying a queen, an asset that would be useful if the movies ever deemed Mera worthy of the Atlantean crown (which they should, she would clearly be a better leader than Momoa's Aqua-dude).
It's a casting idea that has been brought up numerous times since rumours of Heard's departure began, and with good reason too - it simply makes sense.