What is the relationship between Aquaman, as ruler of Atlantis, and Posideon, as god of the sea?
Now it’s true that since Flashpoint Poseidon has been only been seen in Azzarello’s amazing run, that ran from Wonder Woman Vol. 4 #1-35. That said, naturally as the Ruler of the Oceans he’s had a few run ins (swim ins?) over the years with the King of the Seas.