After you unlock a level with the adventure pack figure it then becomes a magic item for that save that has a bomb effect built into it based on the level it unlocked (clock tower drops gears etc.)
Even the old ones do this even though they don't unlock a level in the current game (pirate ship drops cannon balls etc.)
I think the bomb does around 200 damage but honestly can't recall right now.
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Have an extra boomer and punch pop fizz that are opened and a darklight crypt that is still sealed for trade.
You will find that consoles update a bit after the screen status. This means that even when your screen shows things, the content doesn't save immediately and you should wait a little for the system to catch up.