On November 25, 1996, Bagwell joined the New World Order along with Scott Norton, with whom he formed Vicious and Delicious, and legends such as Masahiro Chono and The Great Muta. He turned on partner Scotty Riggs and renamed himself Buff Bagwell. He was part of nWo Japan, the New Japan Pro Wrestling version of the nWo. When he returned to America, he feuded with Lex Luger. Bagwell defeated Luger at Starrcade.
On the April 22, 1998 edition of Thunder, Bagwell suffered damage to several vertebrae and developed spinal shock syndrome after a botched diving bulldog at the hands of Rick Steiner. As planned however, Bagwell won the match with the interference of Rick's brother Scott moments before being carefully placed on a stretcher. Bagwell was then bound to a wheelchair and a neck brace for some time. He returned months later for an interview only to be viciously ridiculed by Hollywood Hogan and shoved to the entryway floor. After having neck surgery, the wheelchair-bound Bagwell returned to WCW on July 6 in his home state of Georgia. Bagwell seemed to have a new attitude and even called out Rick Steiner to offer him his forgiveness. The supposedly invalid Bagwell restrained Rick, however, while fellow nWo member Scott Steiner assaulted him with a steel chair, reaffirming his loyalty to Hogan and the nWo. Bagwell then rose from his wheelchair and helped Scott beat down Rick Steiner. Bagwell and Scott Steiner went on to form an alliance known as "Buff and Bad". In January 1999, the nWo factions reemerged, leading Bagwell and Steiner to side with the Wolfpac. Their alliance ended at Uncensored when Bagwell accidentally hit Steiner with a chair costing him the World Television Championship.
In June 1999, Bagwell engaged in a rivalry with WCW President Ric Flair and Vice President Roddy Piper claiming he was being held back. This led to a three-round boxing match with Piper at the Bash at the Beach in which Bagwell was triumphant. In September 1999, Bagwell feuded with Berlyn when Berlyn issued a challenge to Bagwell, but at Fall Brawl Bagwell was late coming to the arena and "Hacksaw" Jim Duggan replaced Bagwell to face Berlyn and lost. The next night on Nitro Bagwell fought Berlyn but lost thanks to Berlyn's bodyguard The Wall. In November, he defeated veteran Curt Hennig in a retirement match. Bagwell then feuded with Diamond Dallas Page after he made allegations about Page's wife Kimberly. Having spent much of 1999 fighting older wrestlers Bagwell was one of the first to join Eric Bischoff's New Blood alliance, forming a tag team with Shane Douglas. Bagwell and Douglas eventually won the World Tag Team Championship from Ric Flair and Lex Luger giving Bagwell his fifth World Tag Team Title reign and rekindling the feud between Bagwell and Luger from two years earlier. Bagwell was defeated by Luger at Slamboree after submitting to the Torture Rack.On May 9, 2000, following a Thunder taping in Springfield, Illinois Bagwell punched Darrell Miller, a WCW crew member after he and Bagwell began arguing when Miller attempted to carry equipment through a doorway in which Bagwell was standing. On May 15, 2000 Bagwell was charged with battery by the Sangamon County, Illinois State's Attorney's office. WCW responded to the incident by suspending Bagwell for thirty days and stripping him of his half of the WCW World Tag Team Championship.Upon his return Bagwell attempted to win the World Tag Team Title with Douglas once more but failed causing the team to split. Bagwell, now with Torrie Wilson by his side, fought Douglas at Bash at the Beach but lost when Wilson distracted him and sided with Douglas. Bagwell then began a feud with Chris Kanyon who began stalking Bagwell as well as even harassing Bagwell's mother Judy as a psychological attack. Bagwell eventually defeated Kanyon in a match where Judy Bagwell was suspended from a forklift. He rescued his mother despite the surprise interference of actor David Arquette. In August 2000, Miss Hancock, the girlfriend of David Flair, mysteriously became pregnant. Flair was quick to accuse the womanizing Bagwell. This led to a First Blood match at Halloween Havoc with Flair hoping to obtain a sample of Bagwell's blood to prove he was the father of Miss Hancock's child. Bagwell was victorious but Flair got his blood sample when Bagwell's nemesis Lex Luger attacked him after the match leaving him injured and bleeding. Bagwell however was not the father and the entire pregnancy was eventually found to have been a fabrication.
At Starrcade, Bagwell betrayed fellow New Blood member Goldberg by trying to cost him his match with Lex Luger. Bagwell's efforts were unsuccessful but he managed to hit Goldberg with a steel chair after he had pinned Luger. Despite feuding in the past Bagwell and Luger then formed a tag team known as Totally Buff. Totally Buff would go on to defeat Goldberg at Sin after a "planted fan" maced Goldberg, allowing Bagwell to floor him with the Buff Blockbuster and Luger to pin Goldberg. As Goldberg had been warned by Vince Russo that he would be automatically fired if he was defeated. Totally Buff had ended Goldberg's career with WCW, an event that was scripted. In early 2001, Totally Buff joined Ric Flair's Magnificent Seven stable until WCW's closure.
Shortly after WCW was purchased by the World Wrestling Federation in March 2001, Bagwell was one of the first AOL Time Warner contracted wrestlers to accept the offered buy-out on his contract and sign with the WWF. On July 1, 2001, Bagwell faced Booker T at a house show and he appeared on the July 2 episode of Raw is War, facing Booker T for the WCW World Heavyweight Championship. The match went to a no-contest after interference from Stone Cold Steve Austin and Kurt Angle. Bagwell was released from the WWF on July 9 following complaints about his attitude and an altercation with fellow WCW alumnus Shane Helms. It has been alleged that after Bagwell had been seen harassing and bullying Helms about his size, WWF officials put him in a stiff match against the Acolytes and that Bagwell was released when he had his mother call in sick for him afterwards.