The wait is finally over as Brock Lesnar is back in WWE at SummerSlam 2025. The Beast Incarnate shocked the world by confronting John Cena after his loss against Cody Rhodes in the Undisputed Championship match.Lesnar's return has generated a tsunami of reactions from fans as the WWE Universe can't stop sharing their thoughts on the internet. As everyone is stunned by the return of Brock Lesnar, in this article, we will discuss three reasons why the Beast is back at the Biggest Party of the Summer.#3. To become part of John Cena's retirement tourJohn Cena's retirement tour is set to end soon, as he will no longer compete after the end of 2025. Lesnar has been a historic opponent for the Franchise Player, and his return at SummerSlam might have taken place so that he can be part of Cena's final run.A Cena vs. Brock rematch is evident after the veteran destroyed the 17x World Champion with an F5 in the middle of the ring. This occurred right after Cena's match against Cody Rhodes ended.Repeating history means that it is finally time for a rematch between these two legendary stars, and this is why Brock Lesnar is back in WWE.#2. To add a massive surprise to SummerSlam Night 2Seth Rollins' Money in the Bank cash-in already made SummerSlam Night 1 an epic night. However, in the post-show, Triple H disclosed that fans haven't seen anything yet, as major things were in store for SummerSlam Sunday.With the return of Brock Lesnar, it seems evident that his return was added to the Biggest Party of the Summer to incorporate a genuine surprise to the MetLife Stadium show.#1. Brock Lesnar finally gets cleared by WWE's legal teamReports disclosed that Lesnar would only return to the Stamford-based promotion after getting legal clearance from the TKO team. His return at SummerSlam seemingly means that Brock was finally approved for a comeback by the company's legal team.This could be why the King of Kings finally executed his return at the Biggest Party of the Summer. It's possible that if he had gotten clearance before SummerSlam, the Game might have brought him back earlier, as Lesnar always means money for the business.So, these three could be the potential reasons why Brock Lesnar made his return at the recently concluded Premium Live Event.