one piece prb-01 booster box such as Mihawk from OP01 and Doflamingo from OP04 One Piece: Premium Booster PRB-01

In this case it prevents you from becoming an early target while you set up

There are five creatures in the set with the Adventure effect (Beanstalk Giant, Bonecrusher Giant, Lovestruck Beast, Embereth Shieldbreaker, and Tlincalli Hunter), and they are all great additions to the deck, as they provide a decent cheap effect, and they synergize well with other cards when brought back from exile

Under the current rules (as of writing this blog post) both of them would simply die as a state-based action due to the planeswalker uniqueness rule, so nothing special happens

The graphic they added to the Mystery Booster packs had a square background, and the one they used for The List seems to have a rounded background, which creates a telltale difference in the shape of the cards border as you can see on Chatter of the Squirrel and Ancient Den as well as subtle changes in its placement on new border cards, as seen on Boros Challenger