#2 Johnny Universal

This one makes the most sense if the man shows up as a RAW Superstar. It's got a double meaning, of course, as the main championship on RAW is the Universal Championship, but on a more low-key note, the USA Network is owned by NBC/Universal. At the same time, it's also a bit of a nod to Johnny's time in Lucha Underground, where he went by Johnny Mundo. Now he's not just the world, he's the whole universe.
The name works well as a babyface or a heel name and certainly would give him some extra instant credibility as a title contender. If he's a heel and ends up winning the Universal Title with the name, he can double down and call himself Johnny Universal Universal.
As a babyface, he could say that his name means that he is a Superstar that is in WWE to represent everybody. He represents the entire WWE Universe and it's right there. That kind of thing writes itself. Plus, when he does turn bad, you have a built-in reversal of meaning. Johnny isn't the defender of the universe, he is the universe. It's a very versatile, multi-layered name.
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