You cannot summon something that doesn't exist. Pokemon is not a real entity, it is a work of fiction so you cannot summon it. The spell is nothing but nonsense as the spell ingredients should tell you. "A drop of poison ?" Really?
Magic is real and it really does work, but not in the way of fantasy novels or Hollywood productions. If you'd like to learn more about real magic I would suggest the book "Modern Magick" by Donald Michael Kraig.