Advocates for fighting, sea demons either swam in the sea or fought against various marine creatures every day.
In the Ten Thousand Demon Valley, there was a place they very much fancied, the Sea Demon Colosseum.
Unlike the human arena, the Sea Demon Colosseum didn't have any betting or gambling on the games. They simply liked violence, hoping to see the violent aesthetics of blood and fury. Perhaps, this was part of their nature. After all, before awakening, the law of the jungle was the survival law of all marine creatures.
The Sea Demon Colosseum was the only building in the Ten Thousand Demon Valley designed and built by sea demons themselves.
