mtg unstable cards Full Set Review: Order of the Widget! Then destroy all creatures except creatures chosen this way Unstable Mutation — Ultimate Masters

Completing a dungeon will also allow specific ability text on other cards to be used, with Gloom Stalker and the very meta Dungeon Crawler revealed as two such cards that gain benefits from a completed dungeon - double strike and the option to return to the player's hand from the graveyard respectively

Its one thing to build a whole new deck around a theme, but not every theme is supported to that degree

[12] Set: The First Chapter Rarity: Enchanted This card features bright, holographic art and Cinderella in her ballgown shining like her glass slipper

You can keep those permanents around forever if you have a way to remove the finality counters or move them to an opponents permanent