Warning: contains spoilers for Shang-Chi vs. the Marvel Universe #5!
Marvel officially confirms the one superhero Shang-Chi was never trained to fight, and thus cannot possibly defeat. Trained by his evil father, the Master of Kung-Fu is one of the best, if not the best, hand-to-hand combatant in the Marvel Universe (and by extension the Marvel Cinematic Universe), capable of taking on any number of foes and coming out on top. But in the teaser at the end of Shang-Chi vs. the Marvel Universe #5, written by Gene Luen Yang with art by Dike Ruan and colors by Tríona Farrell, Shang-Chi is destined to fight a battle he cannot possibly win - against Thor, the God of Thunder.
Up to this point, the series has chronicled Shang-Chi's efforts to reform his father's criminal organization, the Five Weapons Society. Alongside his family, all trained extensively in martial arts, the new Supreme Commander tries to put the Society to good use. Unfortunately he finds himself up against his family's traditional values of maintaining loyalty to one's past and against his fellow Avengers who no longer trust him. Shang-Chi finds himself in hot water with every passing issue.
In Shang-Chi vs. the Marvel Universe #5, Shang-Chi ends up falling for Iron Man's trap; he forced Shang-Chi into a situation where he lied about stealing the cosmic cube several issues ago (not to mention he took Iron Man's suitcase armor for himself after refusing to buy it off the sinister Red Dot Collective). Iron Man, Spider-Man, Captain America and Mr. Fantastic all agree: something must be done about Shang-Chi...and the preview for the next issue warns:
"[Shang-Chi] has proven to be the unstoppable force his father trained him to be. But his dad never taught him how to defeat a God..."
Against Thor, Shang-Chi has little chance of winning. Thor's powers of flight alone makes him untouchable, even with his family's traditional weapons. For all his skills in combat, Shang-Chi is still only human, and Thor is an Asgardian with far superior strength, speed and durability. One glancing blow from Thor's hammer Mjolnir and Shang-Chi will be defeated in seconds, if not outright killed. Perhaps Shang-Chi could stand a chance if he possessed the Ten Rings from his MCU debut, but he lacks them in the comics (not to mention the rings have very different powers on the page than on screen).
While the end of Shang-Chi shows the titular character being accepted into the larger fold of heroes within the MCU, Shang-Chi vs. the Marvel Universe slowly depicts Shang-Chi losing trust among the Avengers. Using Thor to attack Shang-Chi could be seen as overkill, but the heroes believe they have little choice. Readers will see for themselves exactly how Shang-Chi plans to defeat Thor - if he can survive his assault at all.