I think Wlad has to win by KO, but simply because of the styles and what I saw in the first fight. Fury will be busier than Wlad who has always had to pace himself very, very carefully because of stamina issues. Fury will win rounds just by being more active. The Fury size and awkwardness just seems all wrong for Wlad. He has to let his hands go and try and score a stoppage, but it will leave him open and potentially hurt himself or at least winded.
I struggle to see Wlad outboxing Fury on a consistent basis.