@pokemonrevolution recently presented a new and likely theory for these Grey Thick stamps, which I will quote here: Grey Stamp Theory Grey stamped 1st Edition Base set cards for the most part have commonly been considered to exist because of either A) The ink was low when they were stamped B) The stamp was not pressed down with enough force to create a nice dark color
Want to be able to switch out pokemon
If your Buzzwole is on cooldown, simply retreat it either normally or with a Celesteelas ability then use Celesteela to place it back in and you can use Big Buzz again
Hilda allows players to add any Evolution Pokmon from their deck to their hand while also searching the deck for any Energy card, and this includes special energy, so players can search for cards like Jet Energy and Luminous Energy without having to rely on Colress's Tenacity
At first, I assumed it would be a reprint of the original Base, Jungle, and Fossil sets, with a few extras thrown in