I have thought of an idea for an entire Aquaman trilogy! Here is the summary of the first film: When Prince Orin (Aquaman) is born to Atlanna and Atlan, King and Queen of the underwater kingdom of Atlantis, the superstitious Atlanteans and their King fear the newborn, as he is born with blond hair, supposedly marking him with the Curse of Kordax. Kordax is revealed to have been an ancient Atlantean tyrant who had been killed by Atlan decades ago. King Atlan sentences Orin to be placed on Mercy Reef, where he should suffocate and die. Atlanna steals her child, though, and takes him to the lighthouse of Thomas Curry, her secret human lover. Unbeknowest to King Atlan, Orin's true father is Thomas. Because of this, Orin can breathe on land. Thomas agrees to take care of Orin, and raises him as his son, giving him the human name of Arthur. When Atlanna returns to Atlantis, she is sentenced to death by her own cruel husband. As the years go by, Arthur (unknowing of his real origins and believing his mother died in a boating accident during a storm while he was a baby) begins to notice that he can hold his breath for extended periods of time underwater, and fish seem to mysteriously do as he wants to do, just by him thinking. His father Thomas has a son with another human, and names him Orm, who Arthur looks after and cares for as a big brother. When Arthur becomes a young man, his father leaves him in charge of the lighthouse for a night. The light goes out during a storm, and Arthur sees a fishing boat about to crash into jagged rocks. Without thinking, Arthur jumps out of the lighthouse and dives into the water. Standing on the rocks, he manages to hold the ship back with his bare hands, and telepathically call for dolphins to come to carry the fishermen to safety. When the men are taken to the shore and go to the town, they mutter in shock under their breath about an "Aquaman". Arthur finally confronts his father about his mother. When Thomas explains that Arthur is from Atlantis and is heir to the throne, Arthur decides he must go back to the civilization that deemed him a monster to clear his name. He leaves his father and little brother, who is oblivious to the real reason Arthur is leaving. Arthur dyes his hair black to blend in with the Atlanteans. When Arthur reaches Poseidonis, the capitol of Atlantis, he meets a young Atlantean woman named Mera, who he starts a romantic relationship with and reveals his identity to. She warns him that he will be killed if he is discovered. Despite what she says, Arthur attempts to approach Atlan to show that he is not a menace, he is immediately arrested by royal guards and placed in a prison with Atlantis's former chief scientist, Dr. Nuidis Vulko. The prisoners wear Atlantean prison garb, which includes an orange top made of scales, green gloves and leggings, with a gold belt with an A on the center. Vulko explains to Arthur that he knew his mother, and was the one Atlantean who didn't believe in the Curse of Kordax. He also says that the Atlanteans are too ignorant to realize that Atlan has become a tyrant. Arthur is sentenced to death (again) by the king, who eventually agrees to meet Arthur face to face. Atlan reveals that he himself is none other than Kordax, under a magic spell that has transformed him from his monstrous form into an Atlantean appearence. He killed the real Atlan and took the throne to himself. Knowing that no one will believe the "cursed" Arthur, he is put back into the prison. Vulk reveals that because he is half human, half Atlantean, his powers of strength, speed, air breathing, and telepathy with fish belongs to him and no other Atlantean. Arthur summons a giant whale to break him and Vulko out of the prison. As Vulko goes to his lab to figure out a way to reveal Kordax's true form, Arthur leads a legion of fish against the royal guards as he makes his way to the castle. When he meets Kordax outside of the castle, Kordax attempts to turn the Atlanteans against Arthur by pointing out his superpowers, that are a sign of the Curse of Kordax. Right then, Vulko reverses Kordax's spell, showing his true form to his people. Wielding Poseidon's trident (the King of Atlantis's mark of power), Kordax attacks Arthur. With the help of the sealife, Arthur defeats Kordax, and casts him into an abyss. Picking up the dropped trident, Arthur uses it to cover the abyss, sealing Kordax forever. The Atlanteans finally accept Arthur as their king, though they still are suspicious of him and do not trust him completely, even fearing him somewhat. Arthur appoints Vulko as his royal adviser. Vulko shows Arthur an ancient temple, which Arthur says he will use as his base of operations. When Vulko asks what Arthur means by this, Arthur explains that in Atlantis, he will be known as King Arthur, but humans are not yet ready to know of the ancienct peoples' existence. He must defend the land as the superhero Aquaman.
Like I said I have thought of two sequels to this, which take place in an entire DC cinematic universe, and would tie in (with other films in the universe) to a Justice League film. If you have any feedback it'd be appreciated, and I'd be happy to leave a summary of my other Aquaman/DC universe film ideas as well