Sting's championship reign ended on January 11, 1991, when he was defeated by Flair in a rematch from Starrcade. In the same month, WCW seceded from the National Wrestling Alliance, in the process recognizing a WCW World Heavyweight Championship and a WCW World Tag Team Championship. Sting then feuded with Nikita Koloff in the summer of 1991. He also took part in what many consider to be one of the best matches of 1991, teaming with Lex Luger to face the Steiner Brothers at the first SuperBrawl pay-per-view. That match had also triggered the feud with Koloff when he took a chain-shot intended for his partner Luger (who had been feuding with Koloff at the time). In August 1991, Sting defeated Steve Austin to win a tournament for the WCW U.S. title. At Starrcade '91 Sting went on to win the first ever Battlebowl in which he received a Battlebowl championship ring. At the end of 1991, Sting became embroiled in a feud with the Dangerous Alliance, headed by manager Paul E. Dangerously. The stable targeted Sting because he was the so-called "franchise" of WCW, and vowed to destroy both him and the promotion that he was the face of, although he was also being targeted by Luger, who had once again turned heel and as WCW Champion viewed Sting as a threat. Sting engaged in many matches with Dangerous Alliance members, especially "Ravishing" Rick Rude, who was the group's main star. It was during this feud that he won the first of his six WCW World Heavyweight titles, defeating Lex Luger at SuperBrawl II on February 29, 1992. The feud ended when Sting and his allies, named Sting's Squadron (consisting of himself, Ricky Steamboat, Dustin Rhodes, Barry Windham, and Nikita Koloff) defeated the Alliance (Rude, Austin, Arn Anderson, Larry Zbyszko, and Bobby Eaton) in a WarGames match at WrestleWar in May 1992; the match would get a 5-star rating from Dave Meltzer.
Near the end of Sting's battles with the Dangerous Alliance, the seeds were sown for what arguably became one of the most famous feuds of his career. In April 1992, he defended his WCW World title at The Omni in Atlanta against the 450-pound Big Van Vader. During the match, Vader splashed Sting, cracking three of his ribs and rupturing his spleen. Sting recovered and defended his title against Vader at The Great American Bash in July, dropping the belt to him after missing a Stinger Splash (hitting his head on the ringpost in the process), and receiving a powerbomb. After beating Cactus Jack in a Falls Count Anywhere match at Beach Blast and WCW newcomer Jake Roberts in a "Spin the Wheel, Make the Deal" match at Halloween Havoc, Sting again faced Vader in the "King of Cable" tournament final at Starrcade, where Sting was victorious. The Sting-Vader feud continued into 1993, with Vader defeating Sting in a bloody Strap match at SuperBrawl III. Sting exacted revenge by beating Vader for the World title on March 11 in London, England, but lost it back to him six days later in Dublin, Ireland. Sting then teamed with WCW newcomer Davey Boy Smith to beat the team of Vader and Sid Vicious at Beach Blast, in a match that was set up by a mini-movie that saw an evil midget blow up Sting's boat. At the end of the year, Sting was one of the first people to congratulate the newly-returned Ric Flair after his title victory over Vader at Starrcade. Sting feuded with Vader and Rude through the first half of 1994, defeating Vader in a match for the vacant WCW International World title at Slamboree after Rude was forced to vacate due to his suffering a career-ending injury against Sting in Japan. Soon afterward, Flair turned heel and defeated Sting in a title unification match at Clash of the Champions XXVII. Sting spent the second half of '94 and most of 1995 teaming with new arrival Hulk Hogan in his battles against the Three Faces of Fear and later against the Dungeon of Doom.
At the Great American Bash 1995, Sting defeated Meng to win the WCW United States Championship and defeated Meng in rematch for the U.S Championship at the bash at the beach and he went on to hold the title till November when Sting was defeated by Kensuke Sasaki in Japan.
Sting was on the first ever WCW Monday Nitro when Ric Flair defeated Sting by DQ when Arn Anderson came in to the ring and attacked Flair. At Fall Brawl Sting also with Hulk Hogan, Lex Luger and Randy Savage they defeated the Dungeon Of Doom at the War Games match.
In October 1995, Flair convinced Sting to team with him in a tag match against Arn Anderson and Brian Pillman at Halloween Havoc, as Anderson and Pillman had attacked Flair earlier in the night. Flair was unable to come out for the first part of the match and Sting fended off both Anderson and Pillman alone. Finally, Flair came out, but eventually turned on Sting and reformed the Four Horsemen with Anderson, Pillman, and later Chris Benoit.
Sting then defeated Ric Flair on a Nitro with the Scorpion Deathlock and he wouldn't let go until Luger came out and talked to Sting. At World War III when Sting and Flair had a rematch which Sting won. Sting was in World War III match for the World Heavyweight Championship but the match was won by Randy Savage. Sting kept feuding with the Horsemen for the rest of the year. His alliances with Hogan and Savage led the Horsemen to attack them as well. At Starrcade, Sting defeated Kensuke Sasaki to win the World Cup Of Wrestling, then Sting on to be in a 3 way match vs Ric Flair vs Lex Luger, Flair won by count-out as both Luger and Sting were out on the floor and he stopped Sting from getting back in the ring before the 10 count.
The first part of 1996 had Sting teaming with Lex Luger (who had returned to WCW in September 1995) to win the WCW World Tag Team title from Harlem Heat. The reign was highlighted by the face Sting usually oblivious to the cheating tactics of Luger (a tweener) which became the means by which they usually retained the title. When Luger became temporarily unavailable in March 1996, Harlem Heat member Booker T teamed up with Sting on one occasion to successfully prevent the title from changing hands. A rematch between Harlem Heat and the team of Luger and Sting then came the following night, in which a mutual respect was displayed between Sting and Booker T. Harlem Heat eventually won the title back on the June 24, 1996 edition of WCW Monday Nitro. Sting also received a World title shot against The Giant at Slamboree, but lost after accidental interference from Luger.
In the summer of 1996, Sting was the first to stand up to "The Outsiders" (Kevin Nash and Scott Hall). They had a match at Bash at the Beach with Sting being joined by Randy Savage and Lex Luger. The Outsiders announced they would have a 3rd man in their corner as well. In the opening minutes of the bout, Hall and Nash's partner was nowhere to be seen, but the WCW contingent's 2 on 3 advantage was short lived as Luger had to leave the match early due to an injury. Sting and Savage fought against Nash and Hall until the arrival of Hulk Hogan, who was apparently about to back up the WCW wrestlers until he attacked Savage with his Leg drop finisher in a swerve. The three subsequently formed the New World Order (nWo) at the end of the match, which was ruled a no-contest. The nWo introduced an impostor Sting (played by Jeff Farmer), which led the crowd to believe that Sting had turned his back on WCW during a WarGames match at Fall Brawl. When the real Sting returned he was upset by the fact that many wrestlers believed that he had in fact betrayed WCW despite his denials, that he himself felt betrayed, and so he left WCW by declaring himself a "free agent." He began appearing in the rafters at WCW events; his new silent persona, complete with corpse paint, a trench coat, and longer hair replacing his spiked haircut, was quite obviously inspired by The Crow. He was joined in the rafters on a few occasions by Randy Savage. He also began using a baseball bat as his signature weapon. The nWo, in turn, began to paint Farmer's face in the same fashion to try to continue the confusion, becoming known as nWo Sting. While appearing on a WCW/nWo merchandise special on QVC Sports in late 1999, Sting admitted that Scott Hall initially suggested the idea of painting his face like the character from The Crow. Sting continues to use this type of face paint, occasionally with different designs and the use of color. In an unusual loyalty test, Sting confronted WCW wrestlers in the ring and shoved them a few times with his bat until they were provoked enough to advance on him, at which point he drew the weapon back into a more threatening stance, causing them to stop. He would then hand the bat to the offended wrestler and turn his back, offering them a chance at retaliation. When the wrestler declined, Sting would nod, retrieve the bat, and leave the ring. Following the eventual revelation of his loyalty to WCW, he began coming to the aid of many of these wrestlers (often at the end of a television taping) during group battles with the nWo.
After nearly six months of uncertainty and mystery, Sting finally showed his true colors as a face by single-handedly taking out the entire nWo at Uncensored in March 1997. The pay-per-view had drawn to a close and the nWo were celebrating with their new found partner, NBA star Dennis Rodman, when Sting rappelled down over 70 feet from the roof of the arena via zip-line and began his historic battle against the nWo in which he ended up giving the Scorpion Death Drop to the principal members of the nWo: The Outsiders, Randy Savage, and WCW World Champion Hollywood Hogan. After this attack, he frequently rappelled from the rafters or even came up through the ring to attack unsuspecting nWo members and employ decoy Stings to play mind games during the closing segments of WCW Monday Nitro. Sting's appearances to fight the nWo at the end of almost every WCW Monday Nitro helped to keep and widen the ratings gap between WCW and the WWF throughout the summer. On-screen commissioner James J. Dillon tried many times to get Sting to return to wrestling by making contracts to fight various nWo members, but Sting ended up tearing up the contracts because there was only one man he wanted: Hollywood Hogan.
Sting and Hogan finally met at Starrcade for the WCW World Championship, with Sting winning controversially due to a decision by special guest referee Bret Hart when he reversed the decision made by referee Nick Patrick after Hogan pinned Sting after what he believed to be a "fast count." The match was restarted and Sting made Hogan submit to the Scorpion Deathlock. It was heavily rumored that Sting was supposed to get a "clean" victory in the match, but in the days leading up to the match, Terry Bollea (Hogan), invoking his "creative control" clause in his contract, changed his stance on the outcome from a "clean" finish to a tainted finish that didn't weaken his character. The compromise ended up being the controversial ending of the match. The next night on WCW Monday Nitro, Hogan protested the decision which led to a rematch. The rematch met with the same result and later in the week on the inaugural episode of WCW Thunder, on-camera commissioner J.J. Dillon held the title up and forced Sting to surrender the belt. It was during this situation that Sting said his first words on camera in a year and a half. Upon handing over the belt, he told Dillon, "You've got no guts!" and then turned to Hogan and said, "And you....You're a dead man!" Sting eventually recaptured the title with help from "Macho Man" Randy Savage at SuperBrawl VIII. He went on to have successful title defenses against the likes of Scott Hall, Diamond Dallas Page, and Kevin Nash before losing the title to Savage at Spring Stampede in April 1998, due to interference from Nash.
In the end, Sting amassed three victories over Hulk Hogan, while Hulk Hogan has never been able to defeat Sting. Sting is one of only four wrestlers that have defeated Hulk Hogan without losing to him. Brock Lesnar, Goldberg, and The Rock are all undefeated against Hogan, although Hogan has pinned Sting in a tag team match on Nitro, and he pinned The Rock in a tag team match on Raw. Sting has the highest amount of victories over him.
Later in 1998, nWo split up owing to differences between Hogan and Nash. Nash formed the tweener group known as the nWo Wolfpac. Months later, debate arose as to whether Sting would join one of the factions. Sting made an entrance, sporting the black and white shirt, only to reveal his true stance with the Wolfpac. Soon after, he changed his white face paint to red as well as his ring attire accordingly. Sting held the tag team titles as part of Nash's stable. He and the Giant won the titles at Slamboree. When the team split, Sting was allowed to choose Nash as a partner as a result of his victory at The Great American Bash in Baltimore. Throughout the summer, Sting, along with fellow nWo Wolfpac members Nash, Lex Luger, and Konnan feuded with Hogan's heel faction, nWo Hollywood. Soon after, Sting engaged in a feud with Bret Hart, as a result of Hart's (kayfabe) betrayal after claiming to respect Sting as a result of their similar finishing holds, the Sharpshooter and the Scorpion Deathlock. After suffering (kayfabe) injuries as the result of a bat attack by Hart during a match at Halloween Havoc, Sting disappeared from WCW Television for several months. During this time, the nWo recombined and went fully heel again after The Fingerpoke of Doom incident in 1999. Afterward, Sting left the stable and went out on his own once more.
In the early spring of 1999 Sting made a return on Nitro and then, at Spring Stampede, fought against Hogan, Flair and DDP for the World Heavyweight Championship, with Randy Savage being the Special Guest Referee with Page winning the belt with a bit of help from Savage. Nitro the 12 of April, Sting pinned Ric Flair in one on one match. Then on Nitro 26 of April Sting defeated Page to win World Heavyweight Championship but only to lose the title back to Page a little over an hour and a half later in the main event in a our-way match with Kevin Nash vs DDP vs Goldberg vs Sting when Page pinned Nash, allowing him to win the title without beating Sting. This unsuccessful title defense ended the shortest title reign in WCW history. Sting had a feud with Goldberg and they ended up having a match at Slamboree when they wrestled to a no-contest when both Rick Steiner and Scott Steiner both attacked Goldberg and Sting. It Rick caused Rick Steiner and Sting to have feud and wrestle to no-contest match at the Great American Bash when they both fought to the back and Sting got attacked by 3 dogs. The next night on Nitro Sting saveed Nash for being attacked by Sid Vicious and Savage. At the Bash At The Beach, Team Madness defeated Kevin Nash and Sting in a tag team match were Savage won the World Title. On the Nitro 19 of July Sting defeated Ric Flair to became the President of WCW. Sting then teased a heel turn in the coming weeks to Fall Brawl, Sting defeated Hogan for the World Title after Sting attacked Hogan with a his baseball bat. Sting's heel turn and subsequent attitude change did not go over well with fans. They still cheered him despite the fact that he was supposed to be the bad guy. At Halloween Havoc Sting retained the title against Hogan after Hogan arrived to the ring in street clothes and merely laid down for a 3-count but promptly lost an unsanctioned match to Goldberg at end of the night. Sting attacked the referee Charles Robinson, after the match. Sting was stripped of the title the next night on Nitro cause of his attack on the referee. Sting was given the opportunity to regain the title in a 32 men title tournament, He got to semi-finals after he defeated Brian Knobbs, Meng and Lex Luger but lost to Bret Hart at Mayhem when Luger came to the ring and hit Sting with the baseball bat. Sting returned to being a face. Sting went on to have a feud with Luger. Sting defeated Luger at Starrcade by disqualification when Elizabeth hit Sting with a baseball bat and Luger attacked with a steel chair and the bat and putting Sting out for the rest of the year.
In 2000, Sting ended his feud with Luger by defeating him at Uncensored. At Spring Stampede, Sting defeated Booker T and then Vampiro in the US Championship tournament but Vampiro cost Sting the final match and title to Scott Steiner. After the PPV Sting got in to intense feud with Vampiro. At Slamboree Sting pinned Vampiro. At the Great American Bash Vampiro set him on fire in a "Human Torch Match" (at the heel of the match switched with stuntman, who was set on fire and thrown of the balcony), but came back to even the score with Vampiro. Sting then had a feud with Jeff Jarrett and at Halloween Havoc, Jeff was able to pin Sting with the help of few "fake" Stings and a guitar. After Sting beat Scott Steiner, he was attacked and "injured" by Steiner in 2000, leaving WCW TV for good. However, he returned for the last episode of Monday Nitro, on March 26, 2001 and defeated his longtime rival Ric Flair, embracing in a sportsmanlike fashion at the end of the contest. Fittingly, this was the last WCW match ever, and the final match between Sting and Flair, ending a 13-year, on-again/off-again feud.