Between Charizard and Greninja, which are two of Ash Ketchum's strongest Pokemon, which of these two has the right to call themselves the strongest?

Pokemon Journeys has dropped a major set up for the return of Ash’s Greninja to the anime! The newest iteration of the anime has crossed over its 100 episode milestone, and with it has seen Ash ...

Pokemon Journeys has finally brought Ash Ketchum’s fan favorite Greninja back to the anime after so many years away, and the newest episode of the series demonstrated just how strong their bond ...