Hard to believe that I am holding this card right now when I wasn’t even sure if it existed a few months ago.
For those who aren’t familiar with Pokémon Medallion Battle or the Eevee Ranked Challenge that this promo card was made for, I highly recommend checking out this Pokumon article on the subject.
Below is the story of how I came to be aware of and acquire this card, as well as some brief history about the card itself.
The Story
In the Facebook post announcing this event, it was stated that “Registered players in Hong Kong, Indonesia, Taiwan, and Thailand will receive a physical promo card for the Pokémon TCG”. A month later the event ended, and soon after, Traditional Chinese copies of this card hit the market.
As @rabby250 described in this comment from 2022, it was widely assumed for about 2 years that this card had only been released in Traditional Chinese. This is even echoed in the first line of the Pokumon article I linked. Then, in late 2022, this photo started circulating:
I was informed a few months later (Spring 2023) that this card had been purchased by a notable collector in Indonesia, and that this card is limited to 50 copies. Still, there was no sign of a Thai Medallion Eevee. That was, until mid-December 2023 when a Thai seller randomly posted a copy of this card for sale on eBay.
I messaged the seller to gain information about the card, confirming that only 8 copies were supposedly given out, and I was unsuccessful in talking the seller down to a price I could afford. At that point I had not saved up enough, and I was focused on saving enough money to buy a Fan Club Eevee anyway. So the Thai Medallion Eevee sold in early January, and I carried on.
After months of stalking eBay, Mercari Japan, Yahoo Auctions, etc. for a NM Fan Club Eevee within my budget (to no avail), I randomly decided to check in with the seller of the Thai Medallion Eevee and ask them to notify me if another copy of the card became available. Then, before I could even finish typing my message, I saw that the listing was “in stock”! A second copy had been listed, and I took this as a sign.
So flash forward a few weeks, and I finally have this card in my hand! While I am a bit sad that I’ll have to wait a while until I can afford a Fan Club Eevee again, my rationale was that, if the Thai Medallion Eevee is really as scarce as multiple previous owners stated, a Fan Club Eevee would be comparatively easier to acquire in the future.
Like @eeveeteam, I’ve decided that the next phase of my collection will be focused on trying to acquire all Eevee cards in all languages, so I am extremely excited to knock the Thai Medallion Battle Eevee off my list right away. While I won’t be able to 100% the collection (thanks, Scramble Eevee 
) I can’t wait to expand my Eevee collection further, and collaborate with fellow Eevee collectors and others across the globe to work toward this goal!
Lastly for this update, I’ve added my all-languages tracker to the top of the thread to keep track of my collection progress over time 