The Club are a heel stable which is composed of AJ Styles, Luke Gallows & Karl Anderson. the Club is the WWE's incarnation of the NJPW stable known as The Bullet Club (in which Styles, Anderson & Gallows were members of before they joined the WWE)
The veteran of the team is Luke Gallows as he has appeared in the WWE before and has sported many gimmicks such as an imposter version of Kane, a dimwit known as Festus, and he was also apart of CM Punk's Straight Edge Society group alongside Serena and Joey Mercury. the Straight Edge Society group was when Gallows started donning the name "Luke Gallows". after the Straight Edge Society split up, Gallows became a jobber and eventually left the WWE to other wrestling promotions as Doc Gallows.
AJ Styles made his debut as a face in the 2016 Royal Rumble match entering as the 3rd entrant and confronting Roman Reigns. three months later, Karl Anderson and Luke Gallows appeared in the WWE and ambushed The Usos in their first night. a week after the debut/return of Anderson & Gallows, They then ambushed AJ Styles' opponent, Roman Reigns. after the ambush, AJ Styles confronted Roman Reigns backstage and said he had nothing to do with the attack to which Reigns refused to believe. throughout the weeks, Gallows & Anderson would come to Styles' aide when he didn't want their help. Reigns then brutally assaults Styles due to the fact that he thinks Styles is planning attacks on him. Styles then attacks Reigns and joins the club (but doesn't turn heel yet). after the Extreme Rules ppv, AJ Styles tells the other members of The Club that he has to part ways with them.
a week after they "split up", AJ Styles confronted John Cena (who returned after a shoulder injury) and offers him a welcome back handshake. Anderson & Gallows then arrive and berate AJ Styles for being on good terms with John Cena. as The Club are about to fight AJ Styles and Cena, AJ Styles then ambushes Cena, thus turning heel and re-joining The Club.