He's a chi-com official government superhuman asset. What was he doing here? 
Great Wall was a Chinese villain captured by OMACs.
History
Great Wall was imprisoned beneath Bludhaven by O.M.A.C. Units and escaped the halls of their illegal prison after the units reverted to the unconscious forms of the people they'd been converted from. [1]
Following his escape, he temporarily joined Tapeworm in confronting Robin, Ragman, and Blue Devil in an attempt to get the heroes to release Thunderhand.[1] He was then murdered by The Jury who judged him a criminal due to having been imprisoned alongside them by the O.M.A.C. units[2] The United States Army soldiers that found his body identified him as working for the Chinese government rather than as a generic villain like the rest of the O.M.A.C. facility escapees and attacked and subdued the Jury in retaliation for his murder.[2]
Trivia
His code name comes from his country's famous historic landmark the Great Wall of China.
Related
- 2 Appearances of Great Wall (New Earth)
- 1 Images featuring Great Wall (New Earth)
- Quotations by or about Great Wall (New Earth)
- Character Gallery: Great Wall (New Earth)
Footnotes