The cards are just reminders of the series of triggers each dungeon represents
While this is a fairly impressive spike, its only a 180% rise in a few weeks
Card not found on the other hand was a big part of the early versions of the infamous Card not found decks
The other instant win condition is if the team that is winning has or takes control of the ball with (approximately) 1 minute left on the game clock: they can easily run "quarterback kneel" plays that stop play but keep the clock going until the match is over, and the defense can do nothing about it
Planechase Makes MTG Better, and Doctor Who Fits the Theme Perfectly Magic: The Gathering is often described as many games in one, which helped maintain its position as the most popular TCG for 30 years and counting
Your opponents have to remove, bounce, or use Homeward Path to get their creature back