To Poseidon Rod is one of the seven fishing tools that has made its way to Fisch with the new Atlantis update and you can get it after completing the Poseidon Trials and entering his temple.

Plato wrote that Atlantis had once been a powerful naval ... He further explained that the island nation had been bequeathed to Poseidon, who then fell in love with a woman named Cleito.

You will be magically teleported to the region of Atlantis and can now explore the region to your heart's content! This region is home to the Zeus Trial and Poseidon Trial, as well as the Kraken Pool.