Normally, Scream Tail's attack would not be too imposing, but its interactions with Bravery Charm and Gardevoir ex make this card a potent threat at any stage of the game
While that would have been cute for a regular EX, its extremely risky for a Mega Evolution, losing which instantly ends the game with you on the losing side
But then an event came along - one of seemingly many more to come - which offered basic rewards, but just enough to give you a bit of a nudge and feed back into that overall loop
Gardevoir ex: Embrace the Possibilities
If no UR cards are obtained from those 10 packs, the next time the player purchases 10 of those same packs, the eighth card of the 10th pack is instead guaranteed to be UR rarity
In case you arent aware how this OTK works: If a Duelist has all 5 pieces of Exodia The Forbidden One in their hand at any time, they automatically win the duel