I'm a returning player - the first game I played for a long time was Pokemon Sun. Not really good competitive player, but I think that's understandable. Also, as you can see, I'm not English so my capability of speaking this language is kinda bad.
It's hard to choose just one favorite Pokemon. My favorites are: Lopunny (Mega, swept a Uber team my friend got with her), Glaceon (Eevee is one of my favorites, but I like Glaceon even more), Lugia, Suicune, Weavile and Feraligatr. I can't really choose just one, they all are awesome.
My favorite rival is Silver (although I didn't played Gen 5 and 6). Don't really know why I'm saying that.
My favorite region is probably Alola or Johto.
If I should specialize on 1 type, it would probably be Normal or Water (sorry Ice, you are just way too much bad defensively..).
Well.. bye. ^^