Vivillon does have quite a lot of forms, doesn't it? d: Other than Unown, I don't think any Pokémon has ever had that many forms before. The closest, though, would probably have to be Arceus, as it's got a total of seventeen different forms—one for each type, excluding fairy. Arceus may have a fairy form, but it hasn't been confirmed though, since nobody's been able to a fairy-type plate yet. Rotom would also have to be pretty close, who has about four to five forms. My favorite Vivillon form has gotta be sun, as I find its body colors to compliment each other very nicely. Due to the same reason, I also like meadow. :)
As for Tumblr… I do have an account there, but I haven't logged into it since last year. I forgot its password, too, so if I ever wanted to sign in again, I'd have to reset it. If you ask me, that's a pretty big hassle. d: