|“||You Can't See Me!||„|
|~ John Cena's famous catchphrase.|
|“||Big Brock Lesnar...here comes the pain! God give me strength...forget to give me brain!||„|
|~ John Cena's insult towards Brock Lesnar during one of his signature freestyles.|
|“||The Champ is Here!||„|
|~ John Cena|
Cena started his heel run in October, which was shortly after his debut in June. Cena and Billy Kidman teamed together in a tag team tournament to crown the first WWE Tag Team Champions of the SmackDown! brand, but lost in the first round to the team of Kurt Angle and Chris Benoit. The next week, Cena blamed Kidman for the loss and attacked him, turning heel for the first (and only) time in WWE.
On the next episode of SmackDown!, Cena dressed up as Vanilla Ice and performed a freestyle rap, which had hinted at a new gimmick for the up and coming star. The next week, Cena received a new gimmick, a rapper who'd cut vulgar promos on his opponents, officially beginning his first heel gimmick.
For the first half of 2003, Cena went after the WWE Championship, which incited a rivalry with Brock Lesnar. During the feud, he created a new 'finisher', the "FU", which mocked the "F-5" that Lesnar used. He had a match with Lesnar for the belt at Backlash 2003, but lost after being hit with an F-5. At the end of the year, he became a face again after A-Train turned on him and revealed that he was the sixth man in the now-heel Lesnar's 2003 Survivor Series team, with Cena joining Kurt Angle's team in response to his betrayal.
Cena has remained a face since then.
Outside of the ring, he has been accused of bad behavior by Chavo Guerrero Jr. and Tyler Reks & Ryback.
He lost the title to a returning Brock Lesnar at SummerSlam 2014.