Fedor Emelianenko is returning to MMA, and his first order of business is to defeat the man who knocked him from his throne five years ago.

The former Pride heavyweight champion’s decade-long undefeated run was a phenomenon unlike anything else in MMA history. I can remember gathering around the television with family and friends to watch Emelianenko make the long trek to the Pride ring.

There was always a mystical aura surrounding him. In the ring, he was the Russian nightmare. He was judge, jury and executioner.

But that all ended at a Strikeforce event on June 26, 2010.

Emelianenko stepped into the cage with Fabricio Werdum, a heavyweight contender at the time. Back then, the Brazilian submission specialist didn't possess the well-rounded skills he has now.

Coming into the fight, it was obvious Emelianenko’s best chance for victory was to keep the fight standing. But years of competing against some of the best grapplers in the world can create recklessness. After dropping Werdum with a flurry of strikes, Emelianenko pounced on his opponent without any regard for submissions, desperately looking to end the fight.

And then the unthinkable happened. Werdum isolated an arm and transitioned into a triangle armbar, which initiated the tap in the first round. Emelianenko went on to lose his next two fights in Strikeforce before finishing his career with three wins in M-1.

But the retirement wouldn’t last.