In March 2004 Hennigan debuted on the
Raw brand. His character was depicted as the apprentice and assistant of Raw brand
General Manager Eric Bischoff and given the
ring name Johnny Blaze. The next week his name was changed to
Johnny Spade, and the week after that it was changed to
Johnny Nitro. It's worth noting that both the Johnny Spade and
Johnny Blaze names had been in use before Hennigan used them, by an
independent wrestler and by
Marvel Comics respectively. The Nitro name, a name which finally stuck, was a reference to
Monday Nitro, the flagship show of
World Championship Wrestling which Bischoff had created, and to drive the point home he began using the
Nitro theme music as his
ring entrance music. Nitro acted as Bischoff's apprentice and assistant until the June 7 episode of
Raw, during which he lost a match to
Eugene which carried the stipulation that should he lose the match, he also lose his job.
After leaving Raw, Nitro returned to
OVW and was put into a
feud with his former partner Matt Cappotelli. During the course of the feud
Melina Perez was brought in to the company as Nitro's ex-girlfriend and an ally of Cappotelli, only to
double-cross him and side with Nitro. Not long after, they were joined by
Joey Mercury, forming the
stable "
MNM". MNM wrestled in OVW for around a year, holding the
OVW Southern Tag Team Championship once, before being called up to the main
SmackDown! roster in April 2005. While on SmackDown!, they were put into feuds with the teams of
Rey Mysterio and
Eddie Guerrero, Mysterio and
Batista, the
new Legion of Doom, and
Paul London and Brian Kendrick. MNM held the SmackDown! brand's
WWE Tag Team Championship on three occasions, all in their rookie year on the brand. At May 2006's
Judgment Day MNM dropped the tag team title to London and Kendrick, with Nitro and Melina suddenly
turning on Mercury after the match, breaking up the group. Later in the night, after Melina lost a match to
Jillian Hall in
controversial fashion, she and Nitro complained to SmackDown! General Manager
Theodore Long until Melina slapped Long, getting both her and Nitro (
kayfabe) fired from the brand.
The next week Nitro (with Melina) debuted on the Raw brand in a loss to
WWE Champion John Cena. The following week, Melina faked a
sprained ankle, which allowed Nitro to
roll-up a distracted
Charlie Haas for his first Raw brand win. Nitro immediately joined the hunt for the
WWE Intercontinental Championship, finally defeating champion
Shelton Benjamin at June's
Vengeance in a
Triple-Threat match, which also involved
Carlito. Nitro held the belt, the first singles title of his career, for four months, feuding with several challengers before losing it to
Jeff Hardy on the October 2
Raw. During his time on
Raw, Nitro was also involved in a sporadic rivalry with John Cena, the man who defeated him in his first
Raw match. The feud was unique in that it also involved non-wrestler
Kevin Federline, who appeared on the October 16
Raw from
Los Angeles. Federline was (kayfabe) trained by Nitro for a
January 1 2007 match with Cena, which he ended up winning after outside interference from
Umaga.
In the meantime, Nitro recaptured the Intercontinental title from Jeff Hardy on November 6 when former friend, and General Manager for the night, Eric Bischoff restarted a match that Nitro had been
disqualified from. The very next week, however, Hardy got the title back. In November 2006
MNM reunited on an episode of
Raw to accept an "open challenge" from
The Hardys (
Matt and
Jeff) for
ECW December to Dismember. MNM and The Hardys feuded across the
brands, with the feud intensifying after Mercury was (
legitimately) injured at
Armageddon in December.