I don't think it's Lex. I think it is Pariah's true Apex Predator, and they're going to be nasty as hell.

Now, if I recall correctly, Pariah is just....there, right? He hasn't appeared due to his curse, he's still there from when the last Crisis ended, right?

Because if he suddenly disappears and re-appears somewhere, this is going to get pretty freakin' nasty!!