SummerSlam is WWE's second biggest PLE, so instead of just great matches, some major surprises could happen in New Jersey. Stars might betray their supposed friends, or top names could make triumphant comebacks. John Cena's heel turn at the Elimination Chamber set the tone for the second half of the year. He won the Undisputed WWE Championship from Cody Rhodes and promised to ruin wrestling on his retirement tour.He could make good on his promise again, but that wouldn't be anything new compared to what's happened over the last few months.There needs to be at least one or two major moments at SummerSlam, aside from title changes, that shock the fans. The next five situations could shock the WWE Universe at The Biggest Party of the Summer.#5. Roman Reigns could turn on Jey Uso at SummerSlamEverything seems to be fine between Jey Uso and Roman Reigns. The Yeet Master won at WrestleMania 41, but Reigns was pinned by his mortal rival, Seth Rollins. Jey has maintained a top spot on RAW during Roman's latest hiatus.However, officials can only use the same booking tactics with these two for so long before things get stale and repetitive. Roman returned last year to help Jimmy Uso, and they reconciled for WarGames. This is the same situation now.Despite saving Jey and being mad at Rollins' group, why didn't Reigns return sooner when that group attacked Jey, Penta, Sami Zayn, LA Knight, and CM Punk for months? It was all set up for this tag team match at SummerSlam.WWE still desperately needs to add new wrinkles. The Head of the Table comes and goes all the time. It would shock fans if he turned on Jey and abandoned him. He could then assume leadership of Rollins' group or take off again.#4. Brock Lesnar could return to WWEBrock Lesnar's status in the industry has been a topic of discussion for the past few months. He's known to wrestle a part-time schedule, but always agreed to a new deal when his latest contract was set to expire.This didn't happen over the past two years. His last WWE match was a loss to Cody Rhodes at SummerSlam in 2023.With the second anniversary of his departure looming and his ties to many stars competing in New Jersey, The Beast could surprise the world by crashing SummerSlam.He could align with Paul Heyman or attack his former advocate's allies since they've been name-dropping his nicknames in promos.#3. Bayley could form a new Damage CTRL View this post on Instagram Instagram PostSaying Bayley has been frustrated since WrestleMania is an understatement. Missing this year's Showcase of the Immortals wasn't the first time she wasn't included in plans for the big event.She wasn't booked for WrestleMania 37 in 2021 and missed WrestleMania 38 in 2022 because of an injury. She's taken out her frustration on Lyra Valkyria, whose main crime was holding up her end of a deal made with Becky Lynch.Since Bayley doesn't have control, it would make sense for her to form a new faction, or perhaps revamp Damage CTRL. The faction debuted three years ago. Naomi is currently the Women's World Champion, and The Role Model could align with her.She could also bring back Paige or AJ Lee, or lead NXT call-ups like Lola Vice, Jaida Parker, or Nikkita Lyons. If Cora Jade and Gigi Dolin hadn't been released, they would have been perfect stars for her to guide.#2. Seth Rollins could return to cash in on CM Punk or GuntherOne huge way for WWE to shock the fans at SummerSlam would be if Seth Rollins returns to cash in the Money in the Bank contract. He injured his knee during a match with LA Knight at the last edition of Saturday Night's Main Event. Without a confirmed diagnosis and timetable for how long he'll be out, there's a chance it's part of the storyline. Rollins has long claimed he would never let CM Punk win a title in WWE.Showing up during the World Heavyweight Title match would be a prime spot for the shocking moment. He could either attack both Punk and Gunther and claim the title or wait for Punk to win to ruin his night.#1. The Final Boss could orchestrate a double turnThe Rock is on the TKO Board of Directors and has inserted himself into prominent angles at WrestleMania over the last two years. After John Cena accepted his offer at Elimination Chamber, The Final Boss hasn't appeared in WWE.However, he appeared two days later on Pat McAfee's podcast to talk about the event. Since his involvement has been inconsistent, showing up to judge how his Champion has done would shock the fans. Is he happy with John Cena?Could Rhodes finally join his side, completing the double-turn for both stars? Cena needs to be a hero as his retirement tour winds down, and since The Rock had a hand in his heel turn, it makes sense to influence another major character shift.