There have been two major theories on the identity of the Mr Oz character in the Superman comic books.

The first, and it was intentionally sought by Geoff Johns, that he is Adrian Veidt, Ozymandias, from the Watchmen comic books. Somehow dealing with Dr Manhattan, and manipulating Superman's life.

The second, and that has also been led by Geoff Johns, that it is the Pre-Crisis Jor-El, the father of Superman, doing similar.

Yesterday, we started playing with the name of Mr Oz, reversing it to Zor-M, and wondering who that could be, another Kryptonian possibly, from a similar house? Mr Oz has shown familiarity with Kryptonian matters…

And then this morning, it landed. Mr Oz is… M-ROZ. Or Roz-Em. A Kryptonian who first appeared in Adventure Comics #304.

A Kryptonian who had facial surgery to make him resemble Jor-El's twin brother Nim-El – and thereby Jor-El as well.

And who tried to trick his way into Superboy's life by pretending to be a Red Kryptonite-derived version of Superboy…

…who had to replace him on Earth rather than destroy space time.

And Superboy almost bought it.

But then imprisons Roz-Em in the Phantom Zone forever. okay, mostly forever. Because Roz-Em also appears briefly in Phantom Zone #1.

It really is a fleeting visit, with just a mention…

…and presumably he's in here somewhere.

But two appearances in the entirety of Superman fiction? Of course, that's just the kind of guy Geoff Johns would posit an entire two-year linewide crossover event over.

Oh look, Kryptonian Mr Oz figures looking over a Phantom Zone prison from an upcoming issue of Detective Comics #965, featuring a Tim Drake imprisoned by Mr Oz. What could this mean?