Rotundo during a match in March 2010 at an FCW show
Rotundo was then absent from FCW due to injury, making his return in June. He moved into singles competition, defeating wrestlers including Derrick Bateman, Hawkins, Tyler Reks, and Brodus Clay. In August, FCW Florida Heavyweight ChampionMason Ryan issued an open challenge, which Rotundo accepted. He lost the subsequent championship match by submission. On February 3, 2011, Rotundo defeated Ryan to win the FCW Florida Heavyweight Championship for the first time, but lost the championship to Lucky Cannon immediately afterward. He regained the championship from Cannon three months later, on May 19. In July ans August, Rotundo appeared in multiple untelevised matches before WWE Raw and WWE SmackDown. On September 1, Rotundo vacated the FCW Florida Heavyweight Championship due to injury. Later that month, it was reported that Rotundo had suffered a lacerated kidney, and was expected to be absent for several months to recuperate.
Rotundo returned at the tapings of the January 29, 2012, episode of FCW television, declaring his intentions to reclaim the FCW Florida Heavyweight Championship. On February 2, Rotundo and his brother, renamed Husky Harris, defeated Brad Maddox and Eli Cottonwood to win the FCW Florida Tag Team Championship for the second time. The brothers held the championship until March 15, when they lost it to Corey Graves and Jake Carter. In May 2012, Rotundo made several appearances at WWE house shows, defeating Drew McIntyre. At an FCW live event on June 16 Rotundo defeated Rick Victor to win the FCW Florida Heavyweight Championship for the third time, right after Victor had just defeated Seth Rollins for the title. He lost the title back to Victor on July 13.
In 2012, WWE rebranded FCW as WWE NXT, and Dallas made his NXT television debut in June 20 episode of NXT, portraying a happy-go-lucky and resilient character under the ring name Bo Dallas, where he defeated Rick Victor. In August, Dallas competed in a tournament to crown the first NXT Champion; he was eliminated by Jinder Mahal in the quarter-finals. On the November 7 episode of NXT, Dallas competed in a number one contenders fatal four-way elimination match against Mahal, Drew McIntyre, and Justin Gabriel; despite eliminating McIntyre and Gabriel, Dallas succumbed to Mahal.
On January 26, 2013, at WWE's Royal Rumble Fanfest, Dallas participated in a eight-man NXT tournament for a place in the 2013 Royal Rumble match; he defeated Luke Harper, Conor O'Brian, and Leo Kruger to win the tournament. The next day, Dallas entered the Rumble match at number 16, where he lasted over 20 minutes and eliminated the WWE Intercontinental Champion, Wade Barrett, who returned to the ring and eliminated Dallas. This provoked a brief feud, with Barrett challenging Dallas to a non-title match the next night on Raw, in which Dallas earned a upset victory in his first singles match on Raw. On the February 11 episode of Raw Dallas appeared, attacking Barrett before Barrett's match against Kofi Kingston. Dallas later challenged Barrett for the Intercontinental Championship, but was defeated.
Simultaneously with his feud with Barrett, Dallas entered the NXT Tag Team Championship tournament alongside Michael McGillicutty. The pair defeated Primo and Epico to advance to the semi-finals, but lost to the Wyatt Family (Luke Harper and Erick Rowan) due to Bray Wyatt's interference. In an NXT Championship number one contender's three-way match against Conor O'Brian and Corey Graves, Dallas was prevented from winning by Wyatt, due to Dallas' earlier refusal to join The Wyatt Family. This resulted in a match between Dallas and Wyatt, which Dallas won. Starting in late April 2013, the NXT audience began to turn against Dallas (despite Dallas not changing his character) and started booing him. NXT Tag Team Champion Adrian Neville chose Dallas to replace his injured partner, Oliver Grey, but on May 8, they lost the title to The Wyatt Family. Soon after, Dallas' character began showing subtle villainous traits of being disingenuous.
On the May 29 episode of NXT, Dallas won a battle royal to becomee the number one contender to the NXT Championship. On NXT on June 12 (taped on May 23), Dallas defeated Big E Langston to become the new NXT Champion. He successfully defended the championship against Antonio Cesaro and Leo Kruger during mid-2013. By then, the NXT audience's dislike of Dallas had grown to the point of the crowd literally turning their backs on him while cheering all his opponents, regardless of who he faced. In September, Dallas held an open challenge to determine his next title contender but banned Sami Zayn from competing, so Zayn masqueraded as the masked El Local and defeated Dallas to earn his title shot. The match occurred on the October 16 episode of NXT, and Dallas retained his title by sending Zayn into an exposed turnbuckle. Dallas then faced Adrian Neville in December and lost by countout to retain his title. In a rematch at NXT Arrival in February 2014, Dallas lost the title to Neville, and failed to regain it in a rematch on NXT on March 27. The following month, Dallas attempted to "Occupy NXT", but the crowd turned their backs on him, and he was forced into a match against Justin Gabriel, which he won. Beginning to throw tantrums after failing to get his own way, he was put in a match against Big E on May 22. Dallas subsequently lost the match and was forced to leave NXT as a result. In June, he attempted to return to NXT by appearing as the masked character "Mr. NXT", but was exposed by Zayn and forced to leave.
Starting on the April 7 episode of Raw, WWE started airing motivational-style introductory vignettes for Dallas. Dallas' return to the main roster was in a winning effort, as he defeated Sin Cara on the May 23 episode of SmackDown as well as the May 26 episode of Raw. This was the start of a winning streak, which reached a third victory with the defeat of Xavier Woods on the May 30 episode of SmackDown. Dallas made his first pay-per-view appearance at Payback, where he was scheduled to face Kofi Kingston. However, the match never happened due to interference from Kane. Dallas would face Kingston the following night on Raw in a winning effort. This was declared his 4th victory.
The streak continued with Santino Marella, a second win over Xavier Woods, reached 7 with the defeat of R-Truth and 8 with the defeat of Fandango When it reached 9 with the defeat of Titus O'Neil it was declared "The Greatest Streak in Sports Entertainment". The tenth victory in the streak was a second victory over Fandango.
Dallas established himself as a heel when he attacked El Torito after his eleventh victory (beating Diego) on the July 4 episode of SmackDown. He would go on to defeat El Torito as his 12th victory and then defeated both Diego and Torito in a handicap match as his 13th and 14th victories. WWE released a video of Bo highlighting the "14-Bo" streak he acknowledged. His 15th win came against The Great Khali, his 16th in the streak against Damien Sandow, his 17th against Dolph Ziggler, At Battleground, Dallas participated in the 19-man battle royal for the vacant WWE Intercontinental Championship; he managed to eliminate Sin Cara and Titus O'Neil before being the 16th person eliminated after being thrown out by Dolph Ziggler. Dallas' undefeated streak was ended (17-1) by R-Truth on the July 28 episode of Raw, prompting a small feud between the two.
In late August, Dallas began tormenting Jack Swagger about his loss to Rusev at SummerSlam after Swagger's matches. Dallas began feuding with Mark Henry after defeating him on the September 29 episode of Raw, tormenting him like he did Swagger following Henry's losses to Rusev at Night of Champions. On the October 7 episode of Main Event, Dallas unsuccessfully challenged Dolph Ziggler for the Intercontinental Championship. Dallas then went on to pick up three more wins over Henry in both singles and tag team matches, before being quickly defeated by Henry in a match on the Hell in a Cell pre-show.
After a four month absence due to a foot injury, Dallas made his televised return on the WrestleMania 31 pre-show in March 2015, competing in the André the Giant Memorial Battle Royal where he was eliminated by Hideo Itami. On the May 18 episode of Raw, Dallas reignited his rivalry with Neville, attacking him before and after his match with King Barrett. At Elimination Chamber, Dallas faced Neville in a losing effort. On the August 24 episode of Raw, Dallas interrupting Brock Lesnar about Lesnar lost to The Undertaker at SummerSlam, before Lesnar delivered a number of German suplex on him, and ending the beatdown with an F5.
^JBL says "still undefeated, he's 4 and Bo" after the Kingston victory, indicating the 30 May 2014 loss as "Mr. NXT" to Sami Zayn on NXT episode 102 did not count.
^7 June 2014 at Pan American Center in Las Cruces
8 June 2014 at Santa Ana Star Center in Rio Rancho
21 June 2014 at Santander Arena in Reading, Pennsylvania
22 June 2014 at Bob Carpenter Center in Newark, Delaware
28 June 2014 at Cumberland County Civic Center in Portland, Maine
12 July 2014 at Madison Square Garden in New York City
13 July 2014 at Wildwoods Convention Center in Wildwood, New Jersey
25 July 2014 at BOK Center in Tulsa, Oklahoma
26 July 2014 at Chesapeake Energy Arena in Oklahoma City
27 July 2014 at American Airlines Center in Dallas, Texas
^ abMark Henry def. Bo Dallas 26 October 2014 by Jared Silberkleit:
Prior to the match, Bo declared himself the new “World’s Strongest Man” by virtue of his four recent victories on Raw and SmackDown over the 400-pound former Olympian. After making disparaging remarks to the WWE Universe, and changing his name for one night only to "Bo Wasington" to avoid association with the AmericanAirlines Center crowd, a confident Bo stepped into the ring with Henry.