Sikoa made his WWE debut on October 26, 2021, on the Halloween Havoc special edition of NXT 2.0, by interrupting a segment between the co-hosts Grayson Waller and LA Knight, attacking Waller as Knight rolled out of the ring. Sikoa would face Boa on the January 11, 2022 episode of NXT, which ended in a double countout, but defeated him two weeks later in a Falls Count Anywhere match. At NXT Stand and Deliver, Sikoa would fail to win the NXT North American Championship in a ladder match. Sikoa faced North American Champion Cameron Grimes on the April 12 episode of NXT, but won by disqualification due to Carmelo Hayes and Trick Williams. This led to a triple threat match at NXT Spring Breakin', where Sikoa also failed to win the title. Sikoa would then call himself the next number one contender after Grimes and Hayes' match at NXT In Your House, however he never received a title shot after Hayes won the title; Sikoa would lose to Grayson Waller on the June 21 episode of NXT, ruining his championship aspirations. Sikoa entered a feud with Von Wagner with their match on the July 12 episode of NXT ending in a double countout, but defeated him on the August 2 episode in a Falls Count Anywhere match.
Sikoa made his main roster debut on September 3, 2022 at Clash at the Castle, interfering in the main event match between his cousin Roman Reigns and Drew McIntyre, helping Reigns retain his Undisputed WWE Universal Championship against McIntyre, aligning himself with The Bloodline and turning heel in the process. He made his main roster in-ring debut on the September 9 episode of SmackDown, losing to McIntyre by disqualification when Karrion Kross attacked McIntyre from behind. On September 13, during the NXT 2.0 One Year Anniversary Show, Sikoa made a surprise appearance, and defeated Carmelo Hayes to win the NXT North American Championship. After defending the title three nights later on SmackDown against Madcap Moss, Sikoa was forced to vacate the title on September 20, due to not being an eligible option in the fan vote that was originally set up to select Hayes' opponent. On the September 23 episode of SmackDown, Sikoa would aid Sami Zayn in an attack against Madcap Moss and Ricochet, leading to the pair teaming up to defeat Moss and Ricochet the next week on SmackDown. At Survivor Series WarGames, Sikoa, along with the Bloodline, defeated the team of The Brawling Brutes (Sheamus, Ridge Holland and Butch), Drew McIntyre and Kevin Owens in a WarGames match in his pay-per-view debut. On the March 27 episode of Raw, he challenged Cody Rhodes and was defeated, marking his first pinfall loss on the main roster. On Night Two of WrestleMania 39, Sikoa and Paul Heyman accompanied Reigns in his Undisputed WWE Universal Championship match against Rhodes. Halfway through the match, Sikoa was ejected from the match after he was caught interfering by the referee; however, Sikoa returned at the end of the match to assist Reigns in retaining his championship. At Night of Champions, Sikoa and Reigns unsuccessfully challenged Kevin Owens and Sami Zayn for the Undisputed WWE Tag Team Championships. During the match, The Usos interfered and accidentally attacked Sikoa while aiming for Zayn. The subsequent sequence of events culminated in Jimmy Uso attacking Reigns, and The Usos walking away from The Bloodline. On the June 16 episode of SmackDown, Sikoa's other brother, Jey, turned on Reigns and Sikoa to side with Jimmy. At Money in the Bank, Reigns and Sikoa lost to The Usos in a "Bloodline Civil War" tag team match with Jey pinning Reigns, giving Reigns his first direct pinfall loss since December 2019. At Crown Jewel on November 4, Sikoa defeated John Cena after delivering nine Samoan Spikes to Cena's throat.
On April 7, during night two of WrestleMania XL, Sikoa attempted to assist Reigns against Rhodes again, only to be thwarted by a returning John Cena, who delivered an Attitude Adjustment to Sikoa through the announce table. On the April 12 episode of SmackDown, Sikoa interrupted Paul Heyman during a promo and introduced Tama Tonga, the son of Haku, into the stable while promptly kicking Jimmy Uso out of The Bloodline by brutally attacking him. On May 4, at Backlash France, Sikoa and Tonga defeated Randy Orton and Kevin Owens following interference from the returning Tonga Loa, who joined the stable. On the May 10 episode of SmackDown, Solo Sikoa told Paul Heyman that until Roman Reigns came back, he was in charge of The Bloodline. At Clash at the Castle, Sikoa and The Bloodline began a feud with WWE Champion Cody Rhodes, assaulting him following his title defense against AJ Styles before Randy Orton and Kevin Owens made the save. On the June 21 episode of SmackDown, after his match against Rhodes ended in disqualification following interference by The Bloodline, Sikoa was cornered by Rhodes, Orton and Owens before being rescued by the debuting Jacob Fatu. On the June 28 episode SmackDown, Sikoa kicked Paul Heyman from the stable after Heyman refused to acknowledge him as the new Tribal Chief. After beginning a feud with Cody Rhodes at Clash at the Castle: Scotland, Sikoa, along with Tama Tonga and Jacob Fatu, defeated Rhodes, Randy Orton and Kevin Owens at Money in the Bank in a six-man tag team match after Sikoa pinned Rhodes. On the July 12 episode of SmackDown, Rhodes and Sikoa set up a match for SummerSlam. At the event on August 3, Sikoa failed to win the title from Rhodes in a Bloodline Rules match after interference from the returning Roman Reigns. On the September 13 episode of SmackDown, Sikoa again failed to win the title from Rhodes in a steel cage match. At Bad Blood on October 5, Sikoa and Fatu lost to Reigns and Rhodes after interference from a returning Jimmy Uso, with Sikoa being pinned by Reigns. At Crown Jewel on November 2, Sikoa, Tonga and Fatu defeated Reigns and The Usos in a six-man tag team match.