Remember the ideal time to cast a spell with flash is on the opponent's End Step, right before you untap for your turn
The game checks through a list of these rules any time a player is about to get priority, and uses state-based actions to move cards around and otherwise ensure those rules are enforced correctly
With Dark Rituals, the Rat deck would often stabilize faster, such that if it were on the play, by turn 5 it might have three or even four Rats in play before the Hero can press the Rat deck below 10 life
How Often Do Cards Get Unbanned
The scalper situation is going to happen whenever there's an in-demand product, and it's not very fair on real trainers who just want to collect and play Pokmon for the love of the hobby
When prepared, the creature may cast their spell for the associated cost and at the designated speed, but it'll have to become prepared again to keep doing it