A BGS 10 Black Label, where all four subgrades are perfect, is considered the most prestigious grade in the hobby and commands enormous premiums on the right cards
In total, 151 cards are being given away every month between March and December
It is possible to fall short damage-wise, though, so if you can't knock it out in one hit or get out a Mew or Mew-EX to attack it, it's best to focus on the benchwarmers or chip away at it with Galvantula since Damage Change can possibly be used thanks to Shrine of Memories to heal off any damage you deal
Her -3 is powerful and useful but requires them to have things you want to kill to be of any use
If you love the surprise, the fun of discovery, and the potential for a huge win, then opening packs is for you