WWE may not have realized it, but that storyline had the potential to be one of the best storylines in WWE history.
Allow me to explain.
Kane should have defeated Cena. And in the aftermath, Kane should have continued to torment and manipulate him—eventually turning him to the dark side.
Yes, a John Cena heel turn.
But this is what would have made it different. Kane would have been responsible for damaging Cena and his ultimate decision to embrace the hate.
In the weeks and months that followed, Cena would be a ruthless villain—with Kane in his corner.
I encourage you to draw similarities to the relationship between Darth Vader (Cena) and Darth Sidious (Kane).
As time progresses, everyone fails to stop Cena. Kane relishes in the success he's had with corrupting the face of the WWE.
Until one day, the bell sounds. Undertaker returns.
Undertaker scolds his younger brother Kane, admonishing him for the damage he's caused.
Kane, invigorated by his new-found power, tells Undertaker that he's too late. That the Undertaker is just jealous of him and his new pupil, John Cena.
In the weeks after, Kane continues to poison Cena's mind with lies and deceptions.
In the road to WrestleMania, John Cena continually attacks Undertaker with chairs and other weapons. At one point, he even puts Undertaker through a table.
But the Undertaker does not hate Cena. He hates that his brother, Kane, has manipulated the man that Cena once was.
Therefore, Undertaker is left with no choice. He challenges Cena to a match at WrestleMania in which he vows to save Cena's soul.
Cena argues that his soul doesn't need saving, that he is thinking clearly for the first time in years. Cena promises to end the Undertaker once and for all.
WrestleMania arrives. The Undertaker versus John Cena. Kane is in Cena's corner. No-holds barred match.
Throughout the match, both men put it all on the line. Kane, microphone in hand, urges Cena to punish Taker.
But as the fight progresses, fans can sense that Cena's contempt for Taker waivers, and his respect for the phenom grows.
In the last moments of the match, Undertaker is on the ground, bleeding and injured from attack.
Kane hands Cena the chain. Cena wraps the chain around his fist. But Cena is troubled. He doesn't want to end the Undertaker. Kane yells at Cena, encouraging him to finish it.
Cena walks slowly to Undertaker and drops the chain to the ground. As he reaches for Undertaker, Undertaker locks him into the "hell's gate" submission hold.
Kane proclaims that if Cena taps, he's not the man he thought he was.
Cena taps. The Undertaker wins.
Both Undertaker and Cena are on the ground, tired. Kane enters the ring.
Kane grabs Cena's face and tells him that he's worthless. Cena, in defiance, lifts Kane and delivers an Attitude Adjustment.
Undertaker, although victorious, raises Cena's hand. Undertaker has saved Cena's soul.
Undertaker's fans are happy because the Undertaker's streak is intact. Cena fans are happy because Undertaker has saved Cena's soul. And the added bonus is that Kane played a major role in the Undertaker's last match.
Rest in peace.