Hades stayed on Fish-Man Island for only a day.
He left Fish-Man Island under naval escort.
Having accepted Neptune's invitation, Hades also wanted to see the actual state of Fish-Man Island for himself.
Over the years, the situation on Fish-Man Island had remained under the Kronos Kingdom's control.
Seeing was believing.
Hades could sense that Neptune, the king of Fish-Man Island, harbored no disloyal intentions.
Otherwise, he would not have minded replacing the king of Fish-Man Island.
Arranging for him to die without a trace would have been no trouble for the Kronos Kingdom.
The widow and children he left behind would have been even less capable of resisting the Kronos Kingdom's rule.
Still, having such an "obedient" king made everything much easier, especially when it came to exploiting Fish-Man Island's resources and mobilizing its people.
It allowed them to maximize their gains.
Without King Neptune's cooperation over the years, Fish-Man Island could never have developed this far.
Now that Hades had seen it for himself, he was quite satisfied.
Fish-Man Island generated enormous returns every year, and its importance to the Kronos Kingdom went without saying.
Besides, the future Poseidon had yet to be born. There were still roughly four years to go.
During that time, Hades would refrain from interfering too much with Fish-Man Island. He needed to keep Neptune and Otohime safe and prevent anything from happening to them.
Poseidon would certainly be born—the Mermaid Princess who appeared only once every few centuries.
That was a power capable of destroying the world.
Uranus could raise sea levels, and Poseidon could do the same.
By commanding countless Sea Kings to destroy and sink islands, she could send their fragments to the ocean floor, indirectly causing sea levels to rise.
Cargo sinking to the bottom of the sea, or