The answer to the question "what is the most powerful pokemon?" is not straightforward, as different sources rank the power of pokemon differently. However, according to several sources, including Sideshow, Zavvi, and Dexerto, Arceus is considered the most powerful pokemon. Arceus is a Normal type Mythical pokemon that is the creator of the universe and is thus the closest that the pokemon world has to a god. It has incredible battle performance and is essentially God in the world of pokemon. Other pokemon that are often mentioned as being among the most powerful include Mewtwo, Rayquaza, Zygarde, Eternatus, and Kyurem. However, it is important to note that there is an element of personal preference in these rankings, and different sources may rank pokemon differently based on different criteria.