Board Thread:General Discussion/@comment-5679696-20160509211306/@comment-5805674-20160511170940

 "But I think we should consider that Acheron is  part''  of the Worse Place but still keeping them separated." ''

This. I'm pretty damn sure all the rivers flow FROM the Worse Place to the Underworld, but they are not interchangable. The souls in Acheron don't travel to the Worse Place, they just float in the river endlessly. Also, there is no way out from the Worse Place, whereas now we have souls popping out of Acheron since it was Hades keeping them prisoner there and not any higher force.