For me I would say Me First which copy's the enemies attack but 10 times stronger!
Arceus
Mew
NO. Only ash got that as a choice. You have to catch it in the viridian forest, but it's rare
Pikachu
I know that there are 2 super rare ultra powerful Pokemon in the whole entire Pokemon world.Those Pokemon are Raquaza and Arceus, but what i know is that RAQUAZA is by far the most and i mean the most powerful ultra legendary in the entire Pokemon world.
Get your absol ho-oh and lugia to attak it it will work if you healed your pokemon
Arceus
Caterpie
Arceus is the most powerful, with a base stat total of 720, the current highest. sds ooo
The most powerful water type is Suicune.
The strongest (most powerful) Pokemon is of course rayquaza.
Kyogre.
dragonite
Arceus
mewtwo
Mew
NO. Only ash got that as a choice. You have to catch it in the viridian forest, but it's rare