#1. Brock Lesnar will give Roman Reigns his ultimate WrestleMania coronation
As much as some fans will hate to hear it, WWE was never going to avoid another Roman Reigns-Brock Lesnar match at WrestleMania. When they faced off in 2015, it was Seth Rollins who won after cashing in the Money in the Bank briefcase.
In 2018, Lesnar won clean in a surprising decision. While Reigns has gone on to beat The Beast Incarnate multiple times since then, it hasn't happened at WrestleMania. It's a very different Roman Reigns that we're seeing now than the one in 2015 or even 2018, for that matter.
He is already the guy, but this will be his ultimate coronating moment. To finally beat Brock Lesnar at WrestleMania as well as becoming a double-champion. The last time Reigns competed in the AT&T Stadium, he dethroned Triple H to become the WWE Champion in one of the most underwhelming WrestleMania main events of all time - but that wasn't his fault either.
Lesnar's role in all of this is to eventually elevate Reigns, and that's what is going to happen at WrestleMania 38.