Fatu made his WWE debut on the June 21 episode of SmackDown as a member of The Bloodline stable, assisting Solo Sikoa by taking out Randy Orton, Kevin Owens, and Undisputed WWE Champion Cody Rhodes. At Money in the Bank on July 6, Fatu made his in-ring debut in a six-man tag team match alongside Sikoa and Tama Tonga, defeating Rhodes, Orton and Owens. In the main event of the August 2 episode of SmackDown, the night before SummerSlam, Fatu and Tama Tonga defeated DIY (Johnny Gargano and Tommaso Ciampa) to win the WWE Tag Team Championships, marking Fatu's first title win in WWE. The following night at SummerSlam, Fatu attempted to help Sikoa and threw Rhodes onto the announcer's table, before landing a frog splash from the turnbuckle, seemingly injuring himself and Rhodes in the process. Sikoa ended up losing the match after interference from the returning Roman Reigns. On the August 16 episode of SmackDown, Fatu returned and assisted Solo Sikoa and Tama Tonga in attacking Roman Reigns and subsequently delivering a triple powerbomb through the announce table. The following week on SmackDown, Sikoa had Fatu relinquish one half of the Tag Team Titles to Tanga Loa so that Fatu could be Sikoa's personal enforcer. At Bad Blood on October 5, Fatu and Sikoa lost to Reigns and Rhodes after interference from a returning Jimmy Uso, marking his first loss in WWE. At Crown Jewel on November 2, Fatu, Tonga and Sikoa defeated the original incarnation of The Bloodline (Reigns and The Usos) in a six-man tag team match, with Sikoa pinning Reigns.