So I was contemplating whether to keep pikachu and use 10,000,000 million volt thunderbolt, or evolve it and use stoked sparksurfer. I wanted to try both, but I don't understand how to get it, since it says something about a hat. Is a pikachu with a hat an event Pokemon? Also, Could someone tell which of the 5 z-moves I'm thinking of using is best, and which evolution is best?
(z-moves are: catastropika, 10,000,000 volt thunderbolt, stoked sparksurfer, gigavolt havoc, shattered psyche)