So, logic says that Reigns beats Lesnar at “WM” in order to (theoretically) launch Reigns into the stratosphere. But we've seen Reigns beat Lesnar before. We've seen lots of people beat Lesnar, often in very short, underwhelming matches. It doesn't carry the same weight that it did years ago.
IMO, Reigns can't just beat Lesnar in a “regular” match, nor can he casually squash him in two minutes by spamming finishers. No, in order to make this feel special and different, Reigns has to absolutely demolish Brock. Reigns has to practically beat Brock to death. We have to see Brock like we've never seen him before, bloodied and broken and suffering, getting his ass kicked worse than ever, completely unable to defend himself. I think they need a variation of Lesnar/Orton at “SummerSlam, 2016”, where Orton was bleeding buckets and couldn't defend himself, only this time, it's Brock receiving that thrashing.
I love Roman but it's been a year and a half now and there's no payoff coming for any of this stuff. I can't be bothered to care about the feud that much.