Warning: Contains SPOILERS for Shang-Chi and the Legend of the Ten Rings.
Trevor Slattery returns to the Marvel Cinematic Universe in Mandarin in the All Hail the King One-Shot.
After more than eight years since his MCU debut, Trevor Slattery officially returned in Shang-Chi and the Legend of the Ten Rings. His role continues the thread from All Hail the King, where the Ten Rings kidnaped Trevor. He's been Wenwu's (Tony Leung) prisoner the entire time and turned into a jester/performer for the Ten Rings organization. But, Trevor actually manages to help Shang-Chi (Simu Liu) locate the mystical land of Ta Lo. He is also present for the final battle but uses his acting abilities to play dead so he doesn't have to fight.
By the time it comes to Shang-Chi's ending, fans are likely to be bigger fans of Trevor Slattery and his mythological creature sidekick Morris. The movie doesn't directly set up how or where he could return in the MCU, though. Trevor is last seen in Ta Lo, and he very well could stay in this dimension to stay with Morris. This would also be a safe place for him to live since Trevor is an escaped convict in the eyes of the United States and would be placed behind bars again if he resurfaced. That makes Trevor's MCU future even murkier regarding where and when he could make another appearance.
If Trevor Slattery does return to the MCU again, the best option would be in Doctor Strange in the Multiverse of Madness could be another option if Doctor Strange or Wong travel to Ta Lo's dimension.
There is also the strong possibility that Trevor Slattery's MCU story is over after his Shang-Chi return. Marvel Studios moved past his involvement in Iron Man 3's Mandarin twist by introducing Wenwu in this film. While Trevor is a fun ing character in Shang-Chi, there is not the need for him to be a recurring part of the MCU's storyline. He isn't on the path to becoming a hero or a villain, and Trevor isn't a character the MCU needs to keep bringing back. Shang-Chi and the Legend of the Ten Rings might be Marvel's way of completing Trevor's MCU story instead of setting him up to return.
