After losing two dark matches in the World Wrestling Federation as TNT in July 1993, Vega debuted as Kwang on January 10, 1994. This gimmick incorporated clichéd elements previously used to portay mysterious "Asian" wrestlers, including a mask, a stereotypical "martial arts" moveset, and the use of Asian mist. The WWF aired promotional vignettes in the weeks before his televised debut, which happened on January 22, 1994, when he was the fourth man to enter the 1994 Royal Rumble. During the match, he teamed with the fifth entrant, Owen Hart, battling the face wrestlers to a stalemate until Kevin Nash entered seventh and eliminated all the previous entrants.
Kwang's televised singles debut was on the January 30 episode of Wrestling Challenge, where he, now managed by Harvey Wippleman, defeated Ray Hudson. On the April 18 episode of Monday Night RAW, he lost to the WWF Champion, Bret Hart. On the May 9 RAW, he lost a King of the Ring qualifying match to Razor Ramon. On September 12, he lost to The Undertaker. On January 9, 1995, he was at ringside when Howard Finkel won a Tuxedo match against Wippleman, who then abandoned his role as Kwang's manager. Kwang gradually faded from WWF programming, losing his final match to Hakushi on the April 29, 1995 episode of WWF Superstars.
On May 14, 1995, Kwang appeared in street clothes during the WWF's first In Your House pay-per-view. When Razor Ramon was attacked by Jeff Jarrett and The Roadie, Kwang, portraying a fan in the audience, jumped the guardrail to rescue him. Later that night, Razor introduced him as his friend, Savio Vega.
Vega made his wrestling debut on the May 28 episode of WWF Action Zone, defeating Eli Blu. He then entered the 1995 King of the Ring tournament, as a replacement for the injured Razor Ramon. He qualified by defeating Irwin R. Schyster in the event's pre-show, then defeated Yokozuna by countout in the first round, after interference from Yokozuna's tag partner,Owen Hart, backfired. He then defeated The Roadie with a rollup pinfall. He faced King Mabel in the finals, losing after Mabel hit a splash off the ropes to win the tournament.
The next night on RAW, Vega defeated Intercontinental Champion Jeff Jarrett by disqualification. On July 31, Vega and Razor wrestled Yokozuna and Hart to a time limit draw, then lost a rematch the next week. For the rest of the year, he wrestled in tag matches with Razor and Bob Holly, as well as in singles matches against wrestlers including Waylon Mercy, Sid and Goldust. On January 1, 1996, he teamed for the last time with Razor, losing to The Smoking Gunns.
Vega was the twelfth entrant in the 1996 Royal Rumble, eliminating Dory Funk, Jr. before being eliminated by Vader. The following night on RAW, he lost to Vader. On the March 11 RAW, he wrestled Steve Austin for the first time, resulting in a double countout. This led to a feud, and a series of matches. The first of these happened at WrestleMania XII, both men's WrestleMania debut, which Austin won.
On April 15, Vega challenged Goldust for the Intercontinental Championship. After winning the title, the decision was overruled, the match declared a no contest and the title was held up. The following week, he lost a rematch for the title. On the April 13 Superstars, Rivera, wearing a mask featuring the flag of Puerto Rico and billed as The Caribbean Kid, defeated Austin by pinfall, then unmasked himself. This was Austin's first singles defeat in the WWF, and The Caribbean Kid's sole appearance. Austin won a rematch at In Your House 7: Good Friends, Better Enemies on April 28. One month later, at In Your House 8: Beware of Dog, Vega defeated Austin in a Caribbean Strap Match. According to the stipulations, Austin's manager, Ted DiBiase, had to leave the WWF. This was DiBiase's last appearance on WWF TV until 2005. Austin countered by winning a rubber match.
Vega then feuded with Justin Bradshaw, winning their first match on July 8. On July 21, he lost a rematch at In Your House 9: International Incident. On August 12, 1996, Vega lost his first match by submission to Crush. At SummerSlam, he lost a match to Owen Hart, and was then assaulted by Bradshaw. At In Your House 10: Mind Games, he defeated Bradshaw in a Caribbean Strap Match, ending their feud.
On the September 7 RAW, Vega defeated Hunter Hearst Helmsley. This was followed with a victory over the fake Razor Ramon, who had appeared following the original Razor's departure from WWF. On the December 22 Superstars, he teamed with Jesse James to unsuccesfully challenge Owen Hart and Davey Boy Smith for the WWF Tag Team Championship.
Vega entered the 1997 Royal Rumble, but was eliminated by Austin (the eventual winner) before he could eliminate anyone himself.
In February 1997, Vega joined the Nation of Domination, a stable led by Faarooq, after turning on his partner, Ahmed Johnson. Johnson became the Nation's main rival in the following months. In his first match as a member, he defeated Flash Funk. At In Your House 13: Final Four, he teamed with Faarooq and Crush to win a six-man tag match. In February, he lost consecutive matches by disqualification to Marc Mero and Goldust.
On March 17, 1997, Vega and Crush lost to The Legion of Doom by disqualification. At WrestleMania 13, they teamed with Faarooq to lose a six-man street fight tag match against the Legion of Doom and Johnson. On the next RAW, Vega lost to Johnson by disqualification when The Nation interfered.
Vega then feuded with Intercontinental Champion Rocky Maivia. Like Austin a year earlier, Maivia entered the feud as an undefeated prospect with a major push. On the April 14 RAW, Vega defeated Maivia by pinfall, while holding his tights. At In Your House 14: Revenge of The 'Taker, he once again defeated Maivia, this time by countout. After the match, he attacked Maivia's knee.
On May 11, at In Your House 15: A Cold Day in Hell, Vega wrestled as part of a gauntlet match against Johnson and was eliminated, before Faarooq won it for The Nation. The next night on RAW, he challenged The Undertaker for the WWF Championship, but was disqualified. On June 9, The Nation lost a rematch from WrestleMania 13 against Johnson and The Legion of Doom. After this, The Nation began having internal problems and soon disbanded, when Faarooq expelled several members, including Vega and Crush.
Following his departure from The Nation of Domination, Vega formed his own stable, Los Boricuas, composed of Puerto Rican wrestlers such as Miguel Perez, Jr., Jesus Castillo, Jr., and Jose Estrada, Jr.. Meanwhile, Faarooq had organized The Nation into a black-only group, while Crush had formed The Disciples of Apocalypse, a white biker stable, launching an angle which became known as "The Gang Wars", based on ethnic stereotypes and loosely mirroring some actual gang wars. The three four-member teams wrestled against one another, with none gaining a clear advantage early on. At SummerSlam, Los Boricuas defeated The Disciples of Apocalypse. In the first singles match between former Nation members, Vega fought Crush to a no contest. At Ground Zero: In Your House on September 7, he defeated Faarooq and Crush in triple threat match. At the UK-exclusive pay-per-view, One Night Only, Vega and Pérez unsuccessfully challenged The Headbangers for the WWF World Tag Team Championship. At Badd Blood: In Your House, The Disciples defeated Los Boricuas. Between October and November, Vega also had singles matches, losing to Goldust, Mero and Ken Shamrock.
On the October 27 RAW, Vega and Pérez unsuccessfully challenged The Legion of Doom for the Tag Team Championship. In their next match, they lost to The New Age Outlaws. In December 1997, Los Boricuas and The Disciples exchanged victories. In his first singles contest of 1998, Vega lost to Owen Hart. The next week, Vega and Pérez defeated Taka Michinoku and Scott Taylor. He was the 26th entrant in the 1998 Royal Rumble, and, like the year before, was eliminated by Steve Austin. Vega headlined No Way Out of Texas: In Your House on February, when he replaced the injured Shawn Michaels in the eight-man tag main event, teaming with Triple H and the New Age Outlaws in a losing effort. On the March 9 RAW, he wrestled Triple H to a no contest.
At WrestleMania 14, Vega wrestled in a battle royal, won by Legion of Doom 2000. A week later, Los Boricuas lost to LOD 2000. The Gang Wars continued with matches against The Disciples in April.
The Gang Wars came to an end when the leaders of the three stables faced off in a triple threat match, which Vega won. After the angle, Los Boricuas splintered into two tag teams. On July 6, Vega defeated Brakkus in a Brawl for All tournament boxing match. On August 10, he lost a quarterfinal match to Darren Drozdov. This was his final appearance on WWF TV. He was soon released from his WWF contract.