I love evoking it out and then drawing two cards right before I cast a sweeping recursion spell like Living Death that brings it back for another two cards
not drawing the most important cards, never getting some way to easily add them to the hand, or straight-up bricking (a term which means that you have no way to play any card in your hand at that moment, therefore youre stuck)
Each theme has a small number of possible card sets on that theme, distributed on a rarity basis, such that the specific booster that a player purchases will still be a random selection
An Xyz summon is done by taking two or more monsters on your field with the same level and stacking them on top of each other, then stacking an Xyz monster with the same Rank on top
Just like previous dungeon cards, Undercity starts outside the game and can end up in the command zone for a while
But instead of a clean three-hit combo, this set tripped over itself on the way out the gate