Specialty Events : These include fun or unique formats like Singleton, Artisan, Alchemy, Brawl, and more
Sorry for the tangent, but this really interesting comment you shared from your contact intrigued me one mystery to me has always been if shadowless yellow cheeks Pikachus were printed prior to red cheeks (before being changed back to yellow when shadows were added)
This card have the same problem at Zirnitron , it's a cool card for the deck BUT it's a dead hand too
You could use this in conjunction with Professors Research to maximize your draw power, or use it in place of the staple supporter card, freeing up slots in your limited deck list that can be dedicated to other cards to make your deck more consistent
If you add Commander products, Master editions, Secret Lairs, Universes Beyond Collaborations, and special promotional sets, the total exceeds 1,000 set codes listed on databases like Scryfall
Heres a chart showing what each Quarter Century Bonanza pack looks like: Is there a favorite card you want to see as a Quarter Century Secret Rare, before the anniversary period is over