For more information on future Pokemon TCG products, check out ICv2's Pokemon TCG 2022 release calendar (see "'Pokemon TCG' Product Release Calendar 2022").
Modern fans know it from Pokemon Unite, Pokemon GO, and its continued appearances in competitive formats
Players build decks using Pokmon, Energy, and Trainer cards to battle against each other
Crystal cards were able to change their energy type to match an attached energy card, and only appeared in the Pokmon TCGs e-Card expansions from 2002 and 2003 - named for their compatibility with the e-Reader peripheral for the Game Boy Advance and Nintendo GameCube
Obviously, you dont want to play this straight up as your land drop for turn, but you certainly can if you want
While they don't offer a competitive advantage in battle (they function the same as their standard versions), they are often rarer and serve as beautiful, unique pieces for your digital collection