balloon card yugioh YU-GI-OH! - Illusion Balloons (SECE-EN053) - Secrets of Eternity - 1st Edition Evolves from null Rules Attach a Pokémon Tool to 1 of your Pokémon that doesnt already have a Pokémon Tool attached Wonder Balloons | Card Details

They possess limitation text stating as much in the bottom left corner of their frames, plus their lack of printed effects renders their 'abilities' undecipherable in casual play

The extreme version of that deck makes use of cloning effects to get a bunch of 6/6s with a milling attack trigger

There's also decks that care about copying but they frequently struggle to get critical mana to go off and double something the first time, so this very much could set you up to generate infinite casts of a spell

In January 2021, a PSA 9 copy of the card sold for $233,000 , which at the time made it the most expensive Pokmon card ever sold at auction