While on paper this looks like it could be a reasonably good fight I think it will be decidedly one sided for a number of reasons.
The first reason is simply that Pulev has looked awful in his last few fights and at the age of 39 is clearly past his prime and just holding on for one last big payday which credit to him hes been able to get. He went life and death with Bogdan Dinu who is in no way a top heavyweight and would likely get stopped in short fashion by most of the top 50 fighters in the heavyweight division.
The second reason is that Joshua is in his prime and is clearly maturing as a fighter so shouldn’t struggle versus an old washed up opponent from the previous era at heavyweight. Pulev is also stylistically made for him as hes not going to move around the ring slipping shots and also doesn’t have the hand speed that Ruiz has.

I think that Joshua will get the stoppage between rounds four and eight as he’ll realize Pulev is there for the taking and hopefully won’t box like he did in the second Ruiz fight. I would be incredibly shocked if Pulev won though it would be quite satisfying as it would be karma for the PPV being £25.