If you collected Pokemon cards in your youth, chances are you have an old shoe box storing your collection somewhere in moms basement and gathering dust
Its the same as the rules for turning a Morph or Disguise creature face-up: any effects which trigger from unlocking the door WILL use the stack and allow opponents to respond as normal, so this ends up sounding scarier than it is in practice
Even against decks that are full of creatures you get far more from Chamber than they could hope for
What started out as a Gishath deck, transitioned to Zacama, before ultimately ending up right back where I started
The team of heroes take their turn simultaneously, similarly to Two-Headed Giant, and work together to defeat their common enemy
Of course, there are plenty of future expansions and events for Pokmon TCG Pocket in the works, which will naturally increase the number of desirable cards once more