Well, since I never heard of this "Posiden" guy, I went and changed it to the Greek god guy instead...
DC seems to have tweaked Aquaman so instead of being some goofy-looking blonde guy in tights, he's more like Poseidon these days - if they aren't the same thing, they're close enough that it hardly matters. He even seems a bit surly to the Justice League characters. Bear in mind I don't regularly read superhero comic books these days.