He'll be competitive with the smaller heavys but would get beat up by the others, nothing else to prove. Not good taking these kinds of beatings at 40 so get a fight in Russia and call it a career.
A low level contender, or likely even faded former contender, in Russia as a retirement bout would be appropriate. I mean, he's near 40 so there's no shame in that. I don't think he gets any matches with Joshua or Wilder/Fury winner from this point on.
He can still make some money like Shannon Briggs. Until he becomes as slow as Maskaev in his last fight, he'll certainly be able to have some sort of career, just never on the elite level.
Last nights performance proves he has another year or 2 left and could beat most of the top 10 However the fact he was stopped for the first time and has come up short again against the number 1, may mean he decides to retire. He realistically now is never going to be number 1 or beat the number 1- big money fights are still there though and he can win most of them.
Povetkin wont get the sparring partners he had all at once for this one again,chances are he was at his best last night and couldn't get better preparation for a fight then he had for this one.... Fighting anyone else but Joshua he probably wont need the stacked guys though in his camp bc no one will pose such a threat to him. If the corrupt WBC hadn't taken him out of their rankings theres some good match ups for him but wilder will never fight him and will he wait 2 years for another Joshua rematch ? He will most likely be avoided by the top guys who are looking for title shots,so another fight has to mean something. My guess this fight will have taken all the emotion out of him and he will retire,but?? Guys who are about 6'2 have to train harder for guys over 6'4,not sure what he would mentally have left after a brutal stoppage.