Vader was originally signed with World Championship Wrestling (WCW) in 1991, but was only used sparingly. When he began working for WCW full-time, Vader was paired with a manager, Harley Race, and received a shot at Sting's WCW World Heavyweight Championship on April 12, 1992, but lost by disqualification after punching out the referee. Sting suffered a pair of cracked ribs in the match after taking a Vader splash, though he continued to compete infrequently while recuperating. Vader was placed in a feud with Nikita Koloff shortly afterward, while Sting recuperated. Vader finally received a rematch with Sting on July 12 at The Great American Bash, which he won to become the new WCW World Heavyweight Champion. His reign was short-lived, as he re-injured his knee, forcing him to drop the title three weeks later to Ron Simmons, who substituted for Sting, who was attacked by Jake Roberts earlier that night. Vader was out of action after the Clash of the Champions in September as he underwent knee surgery. Upon his return at Halloween Havoc, Vader sent Nikita Koloff into retirement and broke the back of jobber Joe Thurman (in a legitimate accident), paralyzing him for a few hours. At Starrcade, Vader lost to Sting in the finals of the "King of Cable" tournament. Later, Vader defeated Simmons by taking advantage of a shoulder injury of Simmons's to regain the World Heavyweight Championship. On March 11, 1993, Vader lost the WCW World Heavyweight Championship to Sting in London, England. Six days later, he regained the title in a rematch in Dublin, Ireland. In subsequent weeks, Vader successfully defended the title against Davey Boy Smith, Sting, and Dustin Rhodes.
In late February 1993, White signed an eight-date agreement with the Union of Wrestling Force International (UWFi), where he competed as Super Vader due to legal issues concerning the Big Van Vader name. By September 1993, he was simply known as Vader in the United States. He worked with UWFi for over a year. His greatest triumph under there was a victory in the Best of the World Tournament, which started April 3 and ended August 18, 1994. Vader first defeated Salman Hashimikov and then Masahito Kakihara in the quarterfinals. In the semifinals, Vader defeated Kiyoshi Tamura, and beat Nobuhiko Takada in the finals to win the tournament and the UWFi World Title. He later left the promotion after a financial dispute.
On April 17, 1993, Cactus Jack defeated Vader via countout in a match on WCW Saturday Night. Foley suffered a broken nose and needed 27 stitches for wounds on his face. The match was heavily edited for broadcast, as WCW did not wish to show the severe bleeding. In a rematch on April 23, Vader powerbombed Cactus onto the concrete floor outside the ring. Foley suffered a concussion and temporary loss of feeling in his left hand and leg. Vader believed he had sent Cactus into retirement, but Cactus later appeared in a series of skits involving his powerbomb-inflicted amnesia and a search for his past. In the meantime, Vader began to feud with a new arrival to WCW, Davey Boy Smith. They met at Slamboree in May for Vader's WCW title. Vader lost by disqualification when he hit Smith with a chair, though he retained the title. Vader and Sid Vicious then formed a partnership and called themselves "The Masters of the Powerbomb." They faced off with Smith and his new partner, Sting, at Beach Blast in July. The feud was promoted by a series of vignettes featuring the four wrestlers on a beach and an evil dwarf blowing up a boat. Cactus Jack returned for October's Halloween Havoc pay-per-view to face Vader in a Texas Death match. Cactus stood up to a series of devastating moves near the end of the match, though Vader won when Harley Race stunned Cactus with a cattle prod that kept him down for the count of ten. On March 16, 1994, Foley lost his right ear in a match with Vader in Munich, Germany; Foley's head became trapped in the ropes, which were under excessive tension, causing his ear to be torn off.
Vader had originally been scheduled to face Sid Vicious at Starrcade. The real-life dismissal of Vicious after his stabbing of Arn Anderson in England, however, forced WCW to find a quick replacement. Executive producer Eric Bischoff placed Ric Flair in the match, which was scheduled in Flair's hometown of Charlotte, North Carolina. In the storyline, Vader did not take Flair seriously until he agreed to put his career on the line against Vader's title. Vader dominated the match, but Flair capitalized on failed interference by Race and Vader's weakened knees to win the match with a rollup and end Vader's third WCW World Heavyweight Championship reign. Vader continued to feud with Flair until SuperBrawl IV, when Flair once again defeated Vader, this time in a "Thundercage" match.
Vader then feuded with The Boss, defeating him at Spring Stampede. He also faced Sting at Slamboree for the vacant WCW International World Heavyweight Championship. Sting requested the match rather than be awarded the title after an injury to his original opponent, Rick Rude, and defeated Vader. At Clash of the Champions XXIX, Vader beat Dustin Rhodes and earned the opportunity to face the United States Champion Jim Duggan. In the Starrcade title match, Vader defeated Duggan with the aid of Duggan's 2x4 to win his only United States title.
In January 1995, Vader (now alone after Harley Race suffered a car accident that put him permanently out of WCW) confronted the World Heavyweight Champion, Hulk Hogan, and informed him that he could not avoid the monster. The two met at SuperBrawl V with Vader managing to kick out of Hogan's leg drop after a count of one. The referee was knocked out before Vader hit the Vader Bomb on Hogan. Ric Flair ran to the ring, made the three count, and attacked Hogan, resulting in Vader's disqualification. A rematch was signed, a strap match for the inaugural Uncensored pay-per-view. Flair once again intervened (this time in drag) and managed to cost Vader the match by getting himself carried by Hogan as he touched all four turnbuckle pads. Vader was stripped of the United States Championship on April 23, 1995 for multiple violent offenses. However, Vader gained another opportunity to win the World Title from Hogan at Bash at the Beach in a Steel Cage match. He conspired with Kevin Sullivan and the Dungeon of Doom to gain a psychological edge before the encounter, which Vader lost when Hogan escaped the cage. He then restarted his feud with Flair, based on his frustration at Flair's constant interference in his title matches and Flair's annoyance at his inability to defeat Hogan. At Clash of the Champions XXXI, Vader defeated Flair and Arn Anderson in a 2 on 1 handicap match. Following the event, Hogan grew interested in Vader and asked for his assistance in his developing feud with the Dungeon of Doom, by asking him to join him, Randy Savage, and Sting for WarGames. Vader complied but the storyline never developed as, shortly after, Vader was fired from WCW after he was involved in a locker room brawl with Paul Orndorff.
In the weeks leading up to the WWF Royal Rumble, Vader's debut was heavily hyped on TV (he was billed as "The Man They Call Vader"). He made his first WWF appearance as a participant in the Rumble match. He entered at number 13 and eliminated Jake Roberts, Doug Gilbert, one member of the Swat Team, and Savio Vega. He also fought with his stable-mate Yokozuna. Vader was eliminated by Shawn Michaels before he reentered the ring and started assaulting everyone, including Michaels. Vader defeated Vega on the following Monday Night Raw, before assaulting WWF officials. Eventually, WWF President Gorilla Monsoon demanded that Vader cease his attacks, and received a Vader Splash for his efforts. In storyline, Vader was suspended for his actions (in reality, he needed time off for shoulder surgery).
Jim Cornette campaigned for Vader's reinstatement, and by the time Vader returned, Yokozuna had left Cornette's management. At February's In Your House 6: Rage in the Cage, Vader appeared during Yokozuna's match against The British Bulldog. Yokozuna was about to pin The Bulldog, when Vader attacked him, handcuffed him, and delivered a severe beating. This led to what was supposed to be a one-on-one encounter between Vader and Yokozuna at WrestleMania XII. However, the match became a six-man tag team match pitting Vader, Owen Hart, and The British Bulldog against Yokozuna, Ahmed Johnson, and Jake Roberts. The stipulation was that if Yokozuna's team won the match, he would have five minutes alone with Cornette in the ring; this never occurred as Vader's team won the match when Vader pinned Roberts. Vader then attacked WWF Champion Shawn Michaels after one of Michaels's matches. Vader's attack on Michaels earned him a spot in a six-man tag team match at In Your House 9: International Incident. Vader, Owen Hart, and The British Bulldog teamed up against Michaels, Ahmed Johnson, and Sycho Sid. Vader pinned Michaels to win the match for his team. Vader faced Michaels again at SummerSlam, where Vader won by count-out. Cornette, however, realized that the title could not change hands through a count-out and got the match restarted. This time, Michaels used Cornette's tennis racket and was disqualified. Again, Cornette managed to get the match started over. Finally, Michaels scored a pinfall over Vader.
Vader faced off against The Undertaker in a singles match at the Royal Rumble. During the match, The Undertaker's former manager, Paul Bearer, attacked him and helped Vader win; Bearer then became Vader's manager. Both Vader and Undertaker went on to compete in the Royal Rumble match, during which Steve Austin was eliminated by Bret Hart. However the referees did not see this, as they were attending to Terry Funk and Mankind on the floor, allowing Austin to sneak back into the ring and eliminate both Vader and Undertaker, then Bret Hart, who was busy eliminating Fake Diesel (Glen Jacobs/Kane), and win the Rumble. As a result of this, Vader and the other men Austin eliminated, Bret Hart and The Undertaker, were put into the four-way main event of February's In Your House 13: Final Four for the WWF Championship. Vader, after bleeding profusely, was eliminated by The Undertaker. Bearer then persuaded his two proteges, Vader and Mankind, to go after the Tag Team Title, despite the fact that the two men often brawled between themselves. They failed in their bid to win the tag team gold at WrestleMania 13.
Vader again received an opportunity to face The Undertaker at In Your House 16: Canadian Stampede but was defeated. On the following night's Raw is War, Vader wrestled The Patriot. The Patriot won the match and then went after Bret Hart, who came to ringside during the match. Vader attacked The Patriot, and then brought him back into the ring, where he went for the Vader Bomb. Hart came into the ring and laid the Canadian flag over The Patriot. Vader got down, picked up the Canadian flag, broke it, and started a brawl with Hart. This turned Vader face and served to bring Vader into the USA vs. Canada feud. At Survivor Series, Vader was the leader of Team USA, with Goldust, Marc Mero, and Steve Blackman (replacing the injured Patriot) as they faced Team Canada, composed of The British Bulldog, Jim Neidhart, Doug Furnas, and Phil LaFon. During the match, Goldust walked out on his team. Team USA lost the match after The Bulldog pinned Vader after hitting him with the ring bell. Goldust and Vader feuded throughout the fall and finally faced off at the Royal Rumble, which he won. Goldust eliminated Vader from the Royal Rumble match later that night (Vader entered at number 30). During a final encounter between the two on Monday Night Raw, Kane interfered and attacked Vader.
Kane and Vader had their first in-ring meeting at No Way Out of Texas. Vader lost after a chokeslam and Tombstone piledriver by Kane and was subsequently attacked by Kane with a large steel wrench. Vader was taken away on a stretcher and was kept off of TV for a while. At Unforgiven, a few months later, Vader returned during Kane's Inferno match against The Undertaker. Kane was attempting to leave the match when Vader appeared and fought him back to the ring to continue the match, which Kane lost. Vader and Kane had a rematch at Over the Edge in a Mask vs. Mask match. Vader attempted to use a wrench on Kane (like the one used on him months before), but Kane picked up the victory and Vader lost his mask.
Subsequently, Vader had a series of losses and was reduced to the status of a jobber to the stars. After considering retirement, Vader instead negotiated his own release from the WWF so he could once again wrestle in Japan. His final WWF pay-per-view match was a loss to Bradshaw at Breakdown: In Your House in a No Holds Barred match on September 27. He lost to Edge on Sunday Night Heat in his final televised WWF match. His last match in a WWF ring was on October 25 at a Madison Square Garden house show in a Triple Threat Match with Mankind and Ken Shamrock.