Trevor Slattery is an actor who, having struggled with his career, and suffering from drug addictions and various other legal problems, was then approached by Aldrich Killian to pose as the Mandarin. Taking up responsibility for all of the widespread accidents, caused by Killian's experiments and framing them as bombings, the Mandarin persona presented Slattery as the actual leader of the Ten Rings, becoming the world's most feared terrorist. However, Slattery's role was discovered by Tony Stark, who had Slattery arrested and then sent into Seagate Penitentiary. During his imprisonment, Slattery took advantage of his newly found fame, allowing Jackson Norriss to film and produce a documentary about his life, only to learn Norriss worked for Xu Wenwu, the true Mandarin, who had then proceeded to kidnap Slattery.
Slattery managed to avoid Wenwu's wrath by using his acting skills to entertain the Ten Rings, being allowed to survive in exchange for him then becoming Wenwu's court jester, leading him to live in isolation for many years, with only a Dijiang named Morris as his companion. Eventually, Slattery met Wenwu's children, Shang-Chi and Xu Xialing, along with their friend Katy Chen, who were also sent to be locked up. Slattery accompanied his new party, as they all escaped from the Ten Rings Headquarters, serving as Morris' translator as he guided them into his home realm of Ta Lo. When Wenwu and the Ten Rings followed them into the dimension, Slattery participated in their subsequent battle and survived the Dweller-in-Darkness' attack. Following the memorial, Slattery chose to remain within Ta Lo to be with Morris.
