For the first time in his 30-year career, the Phenom is pulling the curtain back on his heavily guarded persona. The Undertaker: The Last Ride, a five-part docuseries premiering Sunday, May 10 on the WWE Network, offers up an intimate look at the man behind the legendary character as he battles lingering injuries and mental roadblocks. It's an unprecedented move for a guy who's mostly kept the cameras away from his personal life. But, according to the Undertaker, whose real name is Mark Calaway, documenting what could be the final moments of his in-ring career was an important opportunity he just couldn't pass up.

"I knew when we started this that I was getting close to the end and I wanted people to get a little glimpse of what they've been asking for," Calaway told TV Guide. "But also, I wanted them to see what it took on a day-to-day basis for me to get out and be the Undertaker."

As you'll see in The Last Ride, being the Undertaker is a lot harder these days. Because he's no longer that spry 25-year-old who can leap over the top rope to tackle his opponent to the ground, living up to fans' expectations today is a tall order that gets increasingly more difficult as he continues to age and endure more injuries. Now 55, the Undertaker is presented a different, more vulnerable light in the docuseries, which details the physical and emotional work that goes into preparing for each match. But for someone who's used to upholding the mystique of his iconic character, allowing access to the man underneath that well-known persona didn't come easy.

"It was not a natural thing for me. It took a little bit of time before I was comfortable because I am, to a fault, I'm a dinosaur and I still firmly believe in the old ways of our business," Calaway said. "I've moved along as our business has progressed but I carry a lot of the values of the old school. Opening this character up and then seeing the person behind the character, it really went against everything that I've done my whole career. But I just felt like it was time and I felt like I would regret it if I didn't because once the thing's over, I'm not going to have a second chance to do it."

Mark Calaway, <em>The Undertaker:</em> <em>The Last Ride</em>Mark Calaway, The Undertaker: The Last Ride

"Chapter 1" will focus on his only WrestleMania losses so far: WrestleMania 30, which saw Brock Lesnar break his 21-year undefeated streak, and WrestleMania 33, in which he faced Roman Reigns in what was believed to be the final bout of his career. The latter match felt like a passing of the torch as Reigns walked out victorious and Undertaker took what was supposed to be a final curtain call. Ceremoniously leaving his hat, coat and gloves in the ring, he stopped halfway up the ramp to raise his fist one last time --as if signaling that this was it — before disappearing behind the black curtains. But that would not be the end for the Undertaker, who has since competed in numerous matches and is still searching for the perfect way to end his Hall of Fame career. The question is, how does one say goodbye to a character they've played for more than half their life? Not even Calaway himself knows the answer to that right now.

"I never saw the character getting in the ring and having a retirement speech," Calaway said, although he is looking for an "exclamation point" on his career that would serve as a fitting end cap. "I've been looking for that one match that I can say, 'Yeah, that's it. That's the exclamation point on a career. Boom. I can walk away.' And so, I'm struggling. I know what my limitations are, physically, and I'm having to weigh that against the long-term effects of continuing to wrestle. So all these things are intertwined, and they get in the way of each other. You start thinking one way, and then this other part of you thinks, 'Maybe there's a little bit more gas than you think.' And then you go out and you do it and something goes awful and it's like, 'Oh man, what am I doing?' So it's this constant struggle of when to say, 'When.'"

By all accounts, the Undertaker has had one of the greatest careers in wrestling history. He's held almost every major title in the company, is regarded as the most respected man in the business, and is basically a shoo-in for the Hall of Fame whenever he does decide to officially retire. Given everything he's accomplished and his declining health, many question why he would continue to put his body on the line when there's nothing left to prove.

"It's easy to sit on the outside and [say], 'Is he greedy? Does he want the money? Does he want the fame?' But those things are the farthest thing from my interests. I've never enjoyed being a celebrity. It's the love of what I do," Calaway explained.

That stalwart love of the business is what has kept the Undertaker going despite the toll it takes on his body, including numerous concussions, hip replacement surgery and the kind of pain that would turn your knuckles white. But in 2019, when he was left off the WrestleMania card for the first time in 19 years, it seemed like the Undertaker was finally ready to hang up his boots for good. And then AJ Styles happened.

"At that point, I was pretty content," Calaway said. "I'd already kind of come to grips with the fact that my days, especially with WrestleMania, it was time to move on. And then, the match with A.J. presents itself. We've both been in the business for a while and our paths had never crossed. That's very unusual to never have a match with [someone of that stature] and I really hold him in very high regard as an in-ring performer and as a human being."

Their on-air feud culminated at WrestleMania 36 in one of the most unique matches to date. As a result of the COVID-19 outbreak, which saw the WWE move its live arena shows to a closed set at the company's performance center in Orlando, Florida, the pair's traditional bout was changed to a Bone Yard match at an undisclosed location. The pre-taped battle took on a cinematic tone as the Undertaker and Styles went toe-to-toe around an open grave. In the end, the Undertaker "buried" Styles alive before hopping on his motorcycle and riding off. For many, this could have been a fitting way to close the book his storied career. Whether or not that was the Undertaker's last ride, however, still remains to be seen.

"I just don't know," Calaway said. "I want people to watch [The Last Ride] and kind of come away with their own conclusions of where I'm at. But I have to go into each and every match looking at it that way at this point."

And while we don't yet know when or how he'll actually end his career, what's clear is that Calaway is making the most of every opportunity he has left.

The Undertaker: The Last Ride premieres Sunday, May 10 at 10/9c on the WWE Network.

The Undertaker, WrestleMania 33The Undertaker, WrestleMania 33