Fury/Wlad 2 and Douglas/Tyson

Even if he wins and retires, he's not being remembered as much as Douglas. Douglas pulled off arguably the biggest upset in boxing history and is thought of to this day for it, and the guy that he beat was a much bigger star and feared opponent in the ring that Wlad is, so there's that as well.

It depends on what happens after but he would have to do more to not be remembered as this generations Buster Douglas. If he pulls a Douglas and walks away after his big money defense then it would be hard to call him different except Buster actually won his big fight in exciting impressive fashion rather than the negative fight the Fury won so history wold be kinder to Douglas. So where as Douglas get the lighting in a bottle to explain his outlier, the word fluke would get thrown around much more with Fury.