How do you know he created a divergent timeline? There's absolutely nothing to indicate that that's how time travel in the DC universe works. In fact, quite the opposite. Characters have time-traveled and returned to their exact timelines before. Even that's not any real indication that that's how things work now, with this whole "New Earth" crap in the wake of IC.
I find it pretty hard to swallow that the benevolent, heroic Supernova is actually an earlier version of Booster, too. He went from self-serving, opportunistic prick to true hero, then back to self-serving, opportunistic prick? I know people have changes of heart, but that's a complete character shift and then a complete regression, which is kind of ridiculous, even for comics.
