#2 Lesnar brings the UFC Heavyweight Championship to the WWE
UFC and WWE are two different companies that offer entirely different products. But, there is someone common between these two and that is Brock Lesnar (other fighters are exceptions).
Lesnar has worked for both, the WWE and the UFC. He has plans to fight against the current UFC Heavyweight Champion in the octagon but nothing has been fixed regarding their fight yet.
The current Universal Champion has been negotiating a deal with the UFC and there is a high chance that we will see his comeback soon. While there is no fixed date but the fight will happen soon according to various sources.
If Lesnar faces Cormier then he could whip him to become the new champion of the UFC. Now, considering that, he might even bring that title to the WWE, to gain a bit of an advantage over Rollins. This would also benefit the WWE as they will get a lot of attention from the UFC fans.