(It's not a creature.) If an ability triggers whenever an opponent loses life and its effect causes you to gain life, such as the ability of Exquisite Blood, this will loop until either you win the game or a player takes an action to break the loop
Enchantment - Aura Color tag templates(None) Not Dead After All Until end of turn, target creature you control gains "When this creature dies, return it to the battlefield tapped under its owner's control, then create a Wicked Role token attached to it." (Enchanted creature gets +1/+1
As Magic players, we all sit somewhere between "100% player" and "100% collector" on the proverbial Player/Collector spectrum
The ultimate ability, though, is astonishing
Despite initial concerns that the mechanic would lead to too much rules complexity, the designers at Wizards of the Coast kept things manageable
All this to say that the new Mystery Booster product is formulated much the same way, offering a unique experience that we can get at home via Secret Lair offering us Festival in a Box