Since your opponent cant negate the cards activation with cards of the same type as those discarded (monster, spell, trap) it can stop an opponent from developing their board
The loophole, though, is that you dont need to discard that energy from Mewtwo, so utilising something like the Solrock/Lunatone Energy acceleration engine makes this a safe bet
Luckily, the developers of the game have also created a convenient app called the Pokmon Trading Card Game Card Dex app
Continuing the horror theme are cards reimagined in the style of comic-book front covers for Creepshow, the cult 80s movie heavily inspired by fifties comics like Tales from the Crypt
Released during the Neo series era, this set notably focused on the Gym Leaders and Elite Four members from the Kanto and Johto regions, featuring Pokmon specifically tied to them