union arena bleach booster box arena, vol1 Japanese · Whatnot: Shop, Sell, Connect The booster Pack also includes a chance to find a foil Union Arena - BLEACH: Thousand-Year

It was only available inside random booster packs of the SV3a Raging Surf series that was released in Japan, in September, 2023

I think the Japanese name is the same, but I bet it will get localized as 30th anniversary hide-and-seek! The artwork shows Tentaquil hiding in a big birthday present-style gift box :P I think the card is a joint illustration by Himeno and Arita in like a tag team style.

These can be quite strong Land Restriction lands which only function/accelerate when you have a certain number of lands in play

The win would have been anticlimactic and if the attempt failed, I would have been left with an artifacts deck with no artifacts, so I'm glad I decided to go for a longer game