Credit: WWE.com

On Sunday, at WWE No Mercy 2016, John Cena will vie for AJ Styles' WWE World Championship in a Triple Threat match also involving Dean Ambrose. While both Styles and Ambrose own victories over Cena, it is interesting to note that Cena has yet to defeat Styles in one-on-one competition.

Cena has had his fair share of sensational rivals over the course of his career, and he has overcome every obstacle put in front of him. From The Rock to Randy Orton to Edge, there hasn't been one adversary he hasn't defeated.

AJ Styles should be the sole exception.

The crux of Cena's character for the last decade has been that he refuses to give up, and as a result, he has emerged victorious in almost every one of his feuds. Even if he loses the premier match in the program (e.g. Kevin Owens), he always gets his win back eventually.

Thus far, that has yet to be the case in his ongoing storyline with Styles. The Phenomenal One is currently undefeated against Cena, and if WWE was wise, it would ensure it remains that way.

Credit: WWE.com

The two initially crossed paths upon Cena's long-awaited return to Raw on Memorial Day, and Styles wasted little time making a name for himself at Cena's expense. He immediately attacked Cena and fired the first shot in what would become a heated rivalry.

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In the months that followed, Cena and Styles clashed in every matchup imaginable, including tag team matches and Six-Pack Challenges. They even took their bad blood with them to SmackDown Live when they were drafted to the blue brand in late July.

But on the two occasions they went one-on-one, Styles had his hand raised. He conquered Cena with help from The Club at Money in the Bank before beating him all on his own two months later at SummerSlam.

Styles' clean victory over Cena was a major endorsement of the former face of TNA by the company. Only a handful of notable names can say they have defeated Cena without having to resort to underhanded tactics, and at the biggest blockbuster of the summer, Styles officially joined that illustrious list.

Despite that, Cena is as adamant as ever to not only prove to Styles that he is the superior Superstar, but also to achieve the unimaginable by becoming a 16-time world champion. He has the chance to achieve both feats at No Mercy.

Although Cena has heavily teased in recent weeks that Sunday will be the night he makes history, it is far too early for that to happen. He returned to TV a mere three weeks ago, and Styles is still fresh off his monumental title win at Backlash.

Meanwhile, it is inevitable that they will meet in singles action again, perhaps sooner rather than later on an episode of SmackDown. That said, WWE must resist giving Cena his win back against Styles.

Cena finally toppling Styles would by no means tarnish Styles' credibility. However, it would solidify Styles as no different than anyone else Cena has done battle with before, and WWE has the unique opportunity to avoid that with the current reigning WWE world champion.

It is rare for WWE to go this long without having Cena prevail when it matters most, and that is what has made his character so compelling of late. From his string of excellent matches to his remarkable mic work, he has been putting forth a fantastic effort over the past several months, largely because his booking hasn't been as predicable as it has been in the past.

His ruthless rivalry with Styles has been nothing short of spectacular, but it shouldn't have the same conclusion that every other feud Cena has had. By being the anomaly to the tired John Cena formula, Styles' lasting legacy in WWE will be that much greater.

Graham Mirmina, aka Graham "GSM" Matthews, is a Digital Journalism major at Endicott College. Visit his website, Next Era Wrestling, and "like" his official Facebook page to continue the conversation on all things wrestling.

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