7:05 AM ET

Three weeks ago, the man known as "Nature Boy" stepped between the ropes and into the ring. The pro-wrestling legend had been working out with his trainer for a long time. There was a visitor at the gym on July 1st.

Charlotte was at the ring to watch her dad go through the paces. At one point, Lethal called for Flair to do a "blow-up drill", an exercise designed to test a wrestler'scardio and respiratory system. He was told to hit the ropes 10 times each and then lay down on the mat and get up quickly.

Five years had passed since Flair was on life support for two weeks and intensive care for a month. He said he had a 15% chance of survival. He had a pacemaker installed a year after that.

He told Lethal that he would only do the drill with more reps. Charlotte was paying attention.

Charlotte said that he was pushing hard for her. I didn't know what to do.

Charlotte knows how to blow up something. Wrestlers at the WWE Performance Center are trained in the same way. Wrestlers in their early 20s are often fresh off Division I college athletic teams or experience in other wrestling schools.

The drill was executed perfectly by Charlotte's dad.

Charlotte said that it was like a "Rocky" moment, seeing her father push so hard. I was blown away by the fact that he was doing what he was doing and that he was going at it. It was not focused on matter.

One of the greatest wrestlers in the history of the profession, a man whose fame has spanned from the 1970s to today, when he is still featured in the music videos of hip-hop artists, is known as "Nature Boy." He was a 16-time world champion and two-time WWE Hall of Fame member, as well as being the leader of the influential Four Horsemen group, and his classic matches and work on the microphone are revered as icons for any generation. Outside of the wrestling world, Flair's style and swagger, complete with expensive suits, robes, eye-catching jewelry and crocodile-skin shoes, have been mimicked.

In what will be his last match, he will perform on Sunday. The tag team main event of an independent card in Nashville will feature Charlotte's husband, and his father-in-law, as well as Lethal and Jeff Jarrett.

For the past three months, Lethal and his strength and conditioning coach, Rob MacIntyre, have been working with Flair. This match is another chance for him to leave pro wrestling, the business he left an indelible mark on, because he believes he was given a new chance at life. He wants to do it.

"Ego and glory, that's what I'm here for," he said. Also family.

The challenge for those around him is to make sure he doesn't push his body past its limit, which has been difficult.

Lethal said that he needed to go out there and chop someone. People would be okay with that. That wouldn't make sense to him. He's going to try and deliver on a Level 10 match. He's going to bring whatever he can.

Ric Flair hits the ropes as he prepares for his final match on Sunday. Scott McIntyre for ESPN

AIR has always been known for his hard partying. Nightlife is still a part of the "Nature Boy" persona. After the death of his son from a drug overdose, those around him saw that he was no longer the same person. There was a dead person in a hotel room. At the time, he was also going through a divorce. These things are believed to have led to Flair's health issues.

Charlotte believes that her brother's death was his biggest cause of death. I don't like the term self-medication. I believe he was trying to mask the pain with something else. It was not a big deal.

My brother was found by the man. Imagine waking up to find your son dead. People can say he has a problem. His child died as well. For the rest of your life, that will haunt you.

His body was fighting off infections after he suffered a serious injury. Respiratory heart failure and pneumonia were caused by that. He had to relearn to walk after having no recollection of six months of his life. A year later, he had four heart surgeries in a seven week period and had a pacemaker installed to regulate his heart rate.

"You never know if you're going to wake up when you're under that bed," he said. I wake up every time.

Most of the doctors that he's spoken to have told him something. Is it necessary for you to? He replied that he does. He has been cleared by his favorite doctor.

"I don't have concerns about my health," he said. I've passed away. There are fourteen days. It's life support.

He doesn't have a defibrillar so he won't get hurt during the match. He said that it wouldn't be a problem to fix the pacemaker after it became unplugged on the ring.

MacIntyre found a way not to give his doctor's phone number to him, even though he asked for it many times. There is a problem with his right foot and he has had a shot to address it. Wrestler's family and friends are not worried about his health. They think that even though he is older, he is still safe in the wrestling ring because he knows his way around it.

It doesn't look like the best idea from an outsider. It's like telling Michael Jordan that it's not a good idea to play basketball. I think he knows more than I do. If there's any professional out there, it's this man. The ring is the world that he knows.

Ric Flair trained four times a week ahead of his final match. Scott McIntyre for ESPN

Conrad Thompson is the husband of Megan. He's a mortgage broker, but he's better known in the pro-wrestling world as the founder of the most popular podcasts network. Over the past three years, Thompson has hosted several wrestling conventions, bringing legends, current-day stars and podcasters together under one roof for events, stage shows and autograph signings.

Thompson saw that there was an opening during the SummerSlam weekend in Nashville when he put together Starrcast. SummerSlam was supposed to take place on July 30 but the company didn't want to run its own expo. There was a free Sunday with fans in town, but no wrestling events.

The second Starrcast was scheduled to take place in May of this year. It had to be canceled because of Flair's illness. Thompson saw an opportunity to do one more Starrcast, headline by the Flair roast, because of the ripe date on the calendar and the large amount of people that would come to Nashville for the show.

Thompson thought there would be enough fans in the city to host live wrestling shows on Starrcast. The idea to run a show under the JCP banner, an homage to the classic promotion that went on to become WCW, came about when he talked to his friend David Crockett, a former wrestling executive and broadcaster.

Thompson had an idea in his head. From the 1970s to the 1990s, there was a wrestler synonymous with Jim Crockett promotions.

"I've known Ric for nine years now and every few months whenever we're hanging out or having a few beers, he would just occasionally say, 'What if?' and would kind of freestyle the idea of one."

Thompson asked if he would come back for one more match, at a JCP show in Nashville.

Thompson said that he barely got the sentence out of his mouth. I was expecting that.

Flair wears a shirt with one of his iconic catchphrases: To be the man, you have to beat the man. Scott McIntyre for ESPN

According to both Thompson and Macintyre, Flair brought up the idea of doing one more match before, but he wasn't serious about it until Thompson called. Vince McMahon and "Stone Cold" Steve Austin were involved in a match at Wrestlemania 38, which was watched by "Nature Boy". It made him itch again.

I still didn't think about wrestling, but I enjoyed watching it. Steve did a lot more than I anticipated. Austin is a competitor He is who he is because of that. Which one is Vince? I can't say anything about Vince. He's the most competitive person on the planet.

The competition is what Flair is looking at. He thought he was competing with himself in the room. He had been working with MacIntyre for a year for strength and conditioning. After committing to a final match, Flair reached out to Lethal, who is a teacher at the wrestling school in the area.

During the month of April, he has been training four times a week. He'll leave his home and head to MacIntyre's Hard Nocks South gym in Land O'Lakes, where he'll get stretched out and pushed to get ready for Lethal.

MacIntyre said he's going to stretch out. There will be workouts on a bike or a rowing machine that are either short or long term. Light weights will be lifted in a circuit routine after that. MacIntyre said they will go outside and work on the battle ropes if Flair is feeling good. The trainer said that every workout ends with 100 crunches and sometimes 100 squats, based on the workouts Ric Flair did as a young wrestler. MacIntyre needed to hold him back. It's the case with a lot of athletes but especially with him.

The same challenge has been faced by Lethal. In the ring, Lethal said he has Flair run the ropes and do blow-up drills. Chain wrestling and other basic moves have been done by them. Lethal said that Flair wants to push the envelope. Lethal said that he sometimes has to rein in the legend, but that it was inspiring.

Lethal said that he would wake up before him when he wanted a private workout. I would look at my phone and see a message on the other end. Wake up, m----f---ers. I would love to be in the ring. Get me off the ground. I'm not sure what to think. The message is over.

He wanted to do a suplex off the top or a clothesline over the top. I am afraid. I was wondering why you needed to do that.

Talking flair out of these ideas has been difficult. Charlotte was the only person who was able to talk to him. She said she had to put her foot down when her father tried to do a dive during the final match.

"A lot of our men and women in all companies are 888-609- 888-609- 888-609- 888-609- 888-609- I was not in need of it. It wasn't necessary in your prime time. No.

Charlotte said she will be in attendance for the match and is not concerned about her father since her husband will be with him.

Are we going to see a Shawn Michaels type match? Thompson was asked what type of match he would like to see. I don't think so. We're going to have some fun. I cannot think of a better partner for him to have.

Lethal is unsure. He said he is worried about overexertion because he feels like he is going to push hard to perform at the highest level possible.

"I'm very nervous because I have to perform," he said. I have to walk out to the ring. I have to do some things I haven't been able to do before.

Despite lingering health issues, Ric Flair says he's received the all-clear from his doctors to participate in this final match. Scott McIntyre for ESPN

The air was cold. The match was almost two weeks away. He was frustrated that he couldn't train with Lethal and MacIntyre. After three months of training in the ring with Lethal, he was hoping to turn up the pace even more in the final few days.

"As a matter of fact, I'm not going to drink until I get better," he said. That is a huge deal. I don't want to go to the bar.

The next week, he was back in training. It is difficult to keep him down for a long time. There was a plane crash that almost ended his career. The man behind him was killed by the bolt that hit his umbrella. There were serious health scares in the last two years.

He gave me a gift. He wants me to do this match. Why do I have to come back?

When he was told that he would be phased out in the late 1990s, he lost his confidence. He had an excellent retirement match against Michaels at Wrestlemania 24 in 2008. He did 16 more matches after that.

Thompson said that he wouldn't have wrestled after the event. He did. If he could put his hands on the steering wheel and say, "This is how I want to finish it, this is how I want to end it," that would be a great story.

Richard Fliehr has had a hard life. I don't think there's anything wrong with him wanting to retire as a professional wrestler.

Ric Flair leans on the ropes after a training session in July. Scott McIntyre for ESPN

This is pro wrestling, after all, so there is a storyline accompanying Flair's last match, which has been told through high quality, cinematic videos on the Starrcast website. Lethal is angry that he wasn't included on the card after Lethal trained him. Because he didn't have a place on the card in Nashville, where he and his father Jerry helped put pro wrestling on the map, Jarrett was equally angry at Flair. The AEW wrestler is going to be beside Flair.

In the wrestling business, trust is a big word, according to the man. You are going upside down.

Thompson said that Flair was "polarizing" to a large number of people. He was involved in a civil case that was settled out of court in 2004, after allegations of inappropriate behavior by him and other wrestlers surfaced in a documentary.

A popular recording artist like Bad Bunny featured in a music video about Flair. The song "Ric Flair Drip" was a huge hit in the year. The 1985 wrestling promo about wearing Rolexes and riding in limos is one of the most popular of all time. Many of his successors in wrestling, including Lethal, were influenced by him.

Lethal said that he is his idols. It's like training with lightning in a bottle. A dream become a reality. I'm amazed.

Lethal didn't ask why he wanted to do one more match. He thinks he doesn't need to.

Lethal said that the people don't understand the person. They don't know what it is to be a wrestler. You always stay in the wrestling business once you get in it. There is nothing like a match.

A lot of wrestlers get addicted to drugs and look for a high that comes from being in the ring and having people cheering your name and wanting to reach out and touch you. There isn't anything like that in the world.

A sold-out Nashville Municipal Auditorium with more than 9000 people in attendance is what he sees when he takes a picture. He can see his family in the front row cheering him on. When he told Charlotte he was going to wrestle, he beamed. He loves his daughter as a person and thinks of her as a performer.

"She said, 'I'm proud of you, Dad,'" How large is that?

Some of his family have never seen him perform before. They will be able to do that.

It was one last time.

It will be a part of my life forever. Some people could leave. I wasn't able to.