Magic's primary tournament structure is based on a pool of cards that rotates out on a regular basis (every couple years or so). That pool is called Standard. Typically, these cards were all in-universe, but now they will have licensed properties like Final Fantasy in the pool. There's also a Spider-Man set coming, so this creates official tournament situations where you could have Exdeath and Doctor Octopus facing off on the battlefield. Magic has its own robust setting, so I can't think of words to convey how bizarre this feels to someone that started playing Magic 25 years ago.

There are also expanded card pools that create their own competitive environments (the recent Lord of the Rings set was legal in one of these). I mentioned drafting, which is drafting cards only from specific sets to build a deck. That's how I play Magic; I mostly left the Standard scene behind a few years back.