It's what the title says.
Where's the High Evolutionary? Wundagore is his turf, the New Men or whatever his creations. Yet here's Prestor John. Wikipedia says something about the Evolutionary becoming Galactus' opposite or something, but if he kicked that off by stealing the Surfer's power, and the Surfer clearly has his power back. . .
What's the deal with the Prestor Johns? Are they the same guy from two different points in his life, a Kang/Rama-Tut/Immortus deal? Are they the same guy from different universes? Is Prestor John an order rather than an individual, and these are two members? For that matter, what happened to the Prestor John who was Cable's head of security for his island? He's similar in appearance to the crazy one, but he didn't have the Evil Eye.
Why does Nul want to get home so badly? Can't it destroy, disrupt, and otherwise disorder this world as readily as any other?
What was the Concordance Engine doing there? Setting aside the question of what it actually does, did the Evolutionary build it? Prestor John, using the H.E.'s toys? Did it magically appear there one day because it was fated to do so?
I still don't understand why, with a minimum of 2 fliers on the team, they needed Danny Rand's jet to go to Wundagore? I don't know why they took the train to get to Barcelona, either.
Why was the Surfer so insistent on not letting Prestor John get away? Deal with Nul first, then track down John and his Evil Eye! It doesn't matter if he gets away if the universe is destroyed! Prioritize, Herald!
Other than the last one, I'm not sure any are integral to the plot. The question about the Surfer only is because having him there to fight Nul might have made a difference, perhaps eliminated the need for the quiet Prestor to get involved. Even so, they're all niggling details that my mind's trying to turn over as I read the issues. Maybe Fraction plans to explain it all later, but there's this sense I have of everything being off slightly. Then again, I haven't paid much attention to any of these characters in the last few years, so maybe this is par for the course now.