The cards in this deck are not particularly rare and they're not random, like a pack of cards
The strategy of the PePe deck was simple: Pendulum Summon as many Level 4 monsters as possible and use that to unleash powerful Xyz monsters that can overwhelm an opponent
However, once you've got Sword of the Animist (or Sword of Forge and Frontier) in play, now you've got as many attacks as you have basic lands
They called it situational and unnecessary for the Donquixote Doflaming deck from OP01
Lucky, The 13th Puppy This deck excels at having a wide board with too many characters for your opponent to deal with, and Lucky, The 13th Puppy helps you accomplish that, then rewards you for doing it
While a lot of players are using brackets, plenty don't, and that means this card could just show up on a lot of tables and cause frustration in games