That's an illusion of yours. The Klitschko brothers can't be as great as they used to be anymore. They are past their prime now.
So the question is: could he beat Charr? Yes. Could he beat AJ and Fury? Maybe. Both the fights with them were really close and a couple of punches away from swinging in his favour. He's obviously older and would be the underdog, but imho not by that much. A few adjustments in strategy and he might well beat one or the other.
All opinions, but not having that wlad had his day. Would still put some of the top ten to shame I'll give you that, time catches everyone eventually tho.
Nah, 3 years out now I doubt it. If he can be as good as he was 3-5 years ago, maybe could have an outside chance of beating AJ, but not Fury.
If Usyk becomes champion he could get a one off fight for the age record. I doubt he'd come back for Fury or Joshua tho.
His first fight back would be no earlier than spring 2021, which would be 4 years since his last fight. If he were alive, Jim Jeffries might have some advice for Wlad concerning returing to the ring after years of inactivity.
If Manuel Charr actually exists (fairly sure he died in mid 2018 but no one noticed thus the WBA weren't notified), then he could definitely take that strap off of him.
Could? Absolutely. It's not the craziest of scenarios. If he came back and fought either he would be a live underdog. But would he? I don't know. My gut instinct is no but it would definitely be compelling viewing.