RE: How many different Vivillon formes exist in the TCG?
Pikachu6319: Here's how I go about my living card pokedex. Earliest appearance, in English, rarest version in the set, no reverse holos. For example, the entry for Zekrom would be filled by Zekrom from Black and White Base set, Full Art Ultra Rare. Another example would be Delphox, where I used the holo from XY Beginning set. For stuff from base-fossil, I just go with what I believe are referred to as the unlimited versions i.e not shadowless, first edition etc.
A large part of what influenced these parameters was the fact the collecting the pokedex started as a nostalgia driven endeavour. I knew that I wanted all the RBY and GSC pokemon as I remembered them in TCG form from when I was young.
As for formes, I don't have any guidelines really. It's more flexible in that section of the collection and I just go with whichever printing strikes my fancy. So far, the only foreign card is a promo Spiky-eared Pichu that exists only in Japanese as far as I know. Still waiting for autumn & winter deerling/sawsbuck, hoping for the release of a Vivillon collection, and wondering how Pumpkaboo and Gourgeist's sizes will be reflected in the cards!
Great to know of a fellow living pokedex collector. It was very interesting to read what you did with yours. Sounds like it's a sight to behold.