The story
They called his Pandora's Box trash. It held Poseidon.
Aimar is pulled into the Ocean Age, a world overrun with monsters, and the power he awakens is an SSS grade Pandora's Box. Everyone laughs at it and calls it junk. He gets dumped, then kicked out. Then he finally opens the box, and inside are Poseidon and ten ancient gods, all waking up. The outcast nobody wanted now rules the seas, and every enemy he has ends up bowing at his feet.