Board Thread:General Discussion/@comment-5205908-20160307172003/@comment-1894786-20160307185751

Considering Cora would be the most powerful being in the Underworld (she was better than Regina and less powerful than Rumple, both of whom were stated to be the most powerful sorcerers alive in 3A), and she was TERRIFIED of Hades, I'm going to go ahead and say he's an actual god.

After all, the gods aren't immortal. They can be killed by each other and mortals. They're just ageless. They don't age unless they want to, they don't die from old age, nor do they die from natural causes such as sickness.