You complete a dungeon when the ability on the bottom room resolves
Spellslinger decks, or those that aim to cast a ton of noncreature spells for profit, are incredibly popular in Commander, and for good reason
Its effect is simple yet effective: any spell your opponent casts either costs 1 more, or they let you draw a card
It also acts as a timed tax piece, and it covers not only the creatures exiled, but spells with flashback or unearth, spells from the command zone, casting from the top of the deck with cards like Pantlaza or Ureni
Smugglers Copter Smuggler's Copter was unbanned in Explorer and Pioneer after a long hiatus
Instead, you can simply deny your opponents resources from their deck, and potentially use them for yourself