Tenacity of the Monarchs One of the reasons Monarchs became a meta defining (and destroying) deck was the release of powerful Monarch-themed spells and traps, such as Tenacity of the Monarchs
In some ways, the Budding Expeditioner is even more important than Koga as Mew ex is a two-pointer and losing it to a stray attack can cost you the game: being able to pull it from the Active when its at risk of being knocked out is a lifesaver and can be extremely detrimental to your opponent, especially because it also acts as a free switch-in
That opponent may repeat this process as many times as he or she chooses.
Infodump: Episode 36 pauses in the middle of a duel to fill the audience in on exactly what the deal is with the various dimensions and the war between them
So, when the mechanic returned in a big way in The Lost Caverns of Ixalan and was even supported with a themed preconstructed Commander deck, I knew I was finally able to live the dream of exploring like a madman in Commander
Fortunately, I assume we have fifteen or so years before we have to do quite this much work again