Former WWE Champion Brock Lesnar made a stunning return to WWE tonight at SummerSlam following an incredible main event that saw Cody Rhodes defeat John Cena clean to win back the Undisputed WWE Championship.Lesnar returned to confront a recently turned babyface John Cena, and he attacked him with an F-5 to close the show he has been somewhat synonymous with, in shocking fashion. With tonight's actions, Brock Lesnar only made his case stronger for often being dubbed "Mr. SummerSlam."Interestingly, not only has Lesnar had some of his biggest and best matches at The Biggest Party of The Summer, but he has returned at SummerSlam and destroyed John Cena before, too. Following Cena's last WWE Championship loss at SummerSlam, when he lost to Roman Reigns, Lesnar had made his massive return to confront Reigns, but he stayed in the ring after the show went off air just to have some fun with an already battered Cena.While that return was his first WWE appearance after 18 months, tonight's return marked his return after two years. Speaking of Cena and Lesnar, who can forget the way the former UFC Champion squashed the 17-time World Champion at SummerSlam 2014?Meanwhile, Brock Lesnar's last official match in WWE was also at SummerSlam, back in 2023. In that instance, Cody Rhodes was his opponent in what many thought would end up being his retirement match.Brock Lesnar had made his SummerSlam debut in 2002 and immediately won the WWE Undisputed Championship by defeating The Rock in the main event, a match that cemented him as the next big thing. That wasn’t just a debut; it was a seismic shift in the company’s future.Since then, Lesnar has competed in numerous SummerSlam main events and featured matches across multiple eras, facing icons like The Undertaker, Roman Reigns, CM Punk, and Seth Rollins, and, as mentioned above, John Cena and Cody Rhodes.Brock Lesnar being Mr. SummerSlam isn't just an opinion; it's a certified fact!In case you may think that calling Brock Lesnar "Mr. SummerSlam" is just some gimmick, WWE's social accounts legitimately posted his return, with the caption: "Mr. SummerSlam is back and left us all speechless!"It seems clear that John Cena is set to go back to being an underdog babyface as he encounters perhaps the most dangerous rival he has ever had, and someone who has routinely had his number. Following his valiant performance tonight against Cody Rhodes, expect Lesnar and Cena to go at it very soon, potentially at Clash in Paris.And while John Cena is set to retire from wrestling in 2025, no one knows how Brock Lesnar's return may alter the future of WWE. He does what he wants, when he wants, and shows up whenever he feels like it, and who knows what Lesnar's motivations are as he kicks off his latest run in WWE.