Would he put the Justice League out of business? Would they try to recruit him? Or try to lock him up?
I don't think he would accept it, not really his lifestyle.
Oh he'd still go off and do his own thing, don't get me wrong, but like Superman, he'd have his own Legion Flight Ring, and help the Legion whenever they were in his general area, dealing with the same crisis he was.
Also, I suspect he may get a Green Lantern Ring... Or a Yellow one...
Yellow Ring sounds more likely, now that I think about it.
He'll instantly be regulated to Vertigo.
Come on! they can't even focus a GL book on a non-human! The Doctor has as much a chance of becoming a mainstream hero as Martian Manhunter.
Everyone knows Clark Kent is the only token Alien DC can allow to gain any sort of publicity. Sorry , Salaak you aren't humanoid enough.
Hell , They created Shade and all he got was to be the leader of The Secret Seven and a cameo in JL:Dark.
Here's some Jelly Babies , , you British weirdo. Go hang out with Constantine and Xanadu..