Levincia is primarily utilized in turbo decks that need to recover energy after using it to deal damage and knock out a Pokmon by discarding energy from the board or the hand
For the longest time, players had a quite unfair option to shut down all GY effects, but Konami decided that Abyss Dweller was an unfair card , and it is currently not legal in competitive play
However, I'd love to see casual favorites like Sliver Queen or Deranged Hermit and similar cards get another print, even solely as a Masters mythic or entry in a future Masterpieces set
Yes, you should probably give it a little bit more respect than the other fun decks out there, but Ive heard people say they are going to tech Chatot PLB because Toolbox completely wrecks such and such deck and, to be honest, I laugh a little inside
We ended up with a lot of "cast Vererated Teacher with no level-up creatures" games, which weren't really fun or exciting
This was also the first expansion set featuring the 6th Edition rules changes, and Mark Rosewater designed the set single-handedly