Relive your favorite Final Fantasy momentson the battlefield
Like kicker and cycling, its a deciduous mechanic: Magic designers use it when needed , and its not necessarily in every set, or a set's main mechanic
Even if your other commander is one of the Doctor cards, however, the "Partner with Rory Williams" ability can still search for Rory in a library
Instead of rolling the dice on booster packs, you can just go buy the singles you want, or even check out other regions sets like Japan's Glory of Team Rocket
Oh, and it goes infinite with copy spells and magecraft
Enchantment Possibility Storm Whenever a player casts a spell from their hand, that player exiles it, then exiles cards from the top of their library until they exile a card that shares a card type with it