Whatever is released in Japan when it comes to the Pokemon TCG arrives internationally several weeks later
These were only given to the Japanese contestants at this tournament
The big downside is that it will die to pretty much everything the turn it comes down
The curve outs on the play when you can afford to plot this and cast a 3-drop with haste are going to be powerful

Each Collector Booster will have the following contents: Collector Booster Info 4 Foil commons, common dual lands, or basic lands 2 Foil uncommons 1 Foil showcase basic land 1 Extended-art rare or mythic rare (45 rares, 8 mythic rares) 2 Foil rares or mythic rares, or foil extended-art rares or mythic rares 2 Showcase commons or uncommons, or a borderless card being previewed by Martin Juza on June 8 (5 commons, 6 uncommons) 1 Showcase or borderless rare or mythic rare (8 rares, 17 mythic rares including 5 versions of mythic rare Teferi) 1 Foil showcase common or uncommon, or a borderless card being previewed by Martin Juza on June 8 (5 commons, 6 uncommons) 1 Foil showcase or borderless card, any rarity (5 commons, 6 uncommons, 8 rares, 17 mythic rares including 5 versions of mythic rare Teferi) 1 Foil token In a pack of a Core Set 2021 Collector Booster, you are always getting a minimum of four rares or mythic rares, and about 45% of the time, you will get five