[Nebby Family Giveaway!]

Okay, then I'd like to reanswer , the most powerful pokemon ? - Ash's

In the anime he can potentially kill Mewtwo with a thunderbolt , can revive a stone figure with teardrops , use thunderbolt against ground type pokemon and win.

So it's the only pokemon which is not bound by the laws of pokemon . Even Arceus can't kill it. As long as pokemon exist , it exists.

Pikachu's the boss ! East or west , Ash's is the best!

 

[Nebby Family Giveaway!]

In my point of view , the most powerful pokemon is :

It may sound weird , but in fact Mew is one of the 2 Pokemon (itself and ditto) . So it can transform itself into ANY OTHER POKEMON (including Arceus) and possess the powers of that Pokemon.

Arceus created the universe , fine , But Mew can effortlessly make some new universes with its powers (of Arceus) and can destroy this one at will.

It can even turn into Dialga then , reverse the flow of time , reach the point of time even before Arceus was born , destroy its egg , AND END THE DEBATE.

 

It can make Giratina come back from the distortion world , Make Groudon and Kyogre lovers , Rayquaza and Ekans soulmates , all in the parallel universes. (SOUNDS ABSURD :p)

 

IGN - oneandonly_SOURISH