John Cena is currently on his Farewell Tour in WWE. The 48-year-old legend surprisingly turned to the dark side in his final year as an in-ring performer at Elimination Chamber: Toronto and has since been on a mission to "ruin wrestling" for everyone. The character shift has proven fruitful for Cena, as he captured his record-setting 17th World Title at WrestleMania 41.The Last Real Champion has revisited several of his iconic rivalries since winning the Undisputed WWE Title in Las Vegas. After defeating Randy Orton and CM Punk, there is another name from Cena's past who could challenge him before he hangs up his boots: 27-year veteran AJ Styles. However, the stakes of this match could be even higher than anticipated, as it might turn into a promotional war between WWE and TNA.TNA is set to host its Slammiversary pay-per-view this weekend. The company has confirmed that AJ Styles, who made his in-ring debut in 1998 and went on to become one of the biggest TNA stars in history, is set to make an appearance. Fans are eagerly waiting to see what The Phenomenal One does upon his return to the Nashville-based promotion.In a shocking turn of events, AJ Styles could capture the TNA World Championship in the coming weeks. The reigning champion, NXT's Trick Williams, is set to defend his title in a three-way match against Joe Hendry and Mike Santana. If Trick retains, he could be confronted by a true TNA original in the form of AJ Styles. The Phenomenal One, representing the Nashville-based promotion, could dethrone Trick and bring the championship home.Upon winning the gold, Styles could turn his attention toward Undisputed WWE Champion John Cena. The Phenomenal One and The Unseen 17 had an incredible rivalry in 2016–17, and fans are clamoring for the Stamford-based promotion to revisit the feud before Cena retires in December this year. However, it could be argued that Styles' current position on the roster doesn't make him a believable challenger to The Last Real Champion.Therefore, going back to TNA and winning the world title could make The Phenomenal One a legitimate threat to Cena's championship. Another, and possibly the final, chapter in the story of the two veterans could come in the form of a Champion vs. Champion showdown, with both representing the promotions where they built their legacies. The story is certainly poetic and will surely be a treat to watch for fans if it comes true.That said, it is just speculation for now.John Cena will defend his title against Cody Rhodes at WWE SummerSlam 2025John Cena dethroned Cody Rhodes as Undisputed WWE Champion at WrestleMania 41. On his quest to reclaim the gold, The American Nightmare defeated Randy Orton in the final of the 2025 King of the Ring Tournament at Night of Champions. Winning the coveted crown earned him a rematch against John Cena for the Undisputed WWE Championship at SummerSlam.The two stars are set to sign the contract to make the match official on this week's SmackDown. With only a few weeks left before the PLE, fans are expecting a heated confrontation between the bitter rivals tonight.John Cena has vowed to leave the Stamford-based promotion at the end of the year with the Undisputed WWE Championship. Will Cody Rhodes be able to stop The Last Real Champion in his tracks and regain the title at The Biggest Party of The Summer? Only time will tell!