Four years after Leon moved to England, it happened.
He, his mother and little brother were in Jamaica when they decided to move to the UK.
Their old home was a one-room wooden shack with a zinc roof in a poor area of Kingston.
He had his own place to stay. He was 13 years old when the phone rang at 2am.
The father came to England from Kingston. They didn't live together.
The phone was picked up by the mother of the man. Soon he would hear her crying.
I knew something would happen to my dad because I knew what he was doing.
You know something is wrong when it's a late call. It was frightening. He was murdered, not in his sleep.
It made me more angry and willing to participate in that life. It made me want to be a criminal.
He doesn't know the full story of his father's death, just that he was shot and killed at a nightclub. Growing up in Kingston, he was exposed to the dangers of gang crime.
In the next few years, he was drawn into the world of gang violence.
He would get out, forging a path in MMA against the odds which would lead to an opportunity to win a UFC world title on Saturday.
He was raised in a small neighbourhood in Kingston, Jamaica with his family.
He played football with his friends, built and flew kites in the Caribbean breeze, and climbed trees to pick mangos.
One of the dangers of life was the fact that he could not imagine his own children having to go through it.
The leader of the local gang was Edward's dad. The general was his name. He became desensitized to gun violence because he was exposed to it so many times.
He says there were gunfights around him.
It was necessary to run and hide. It's weird because you get used to living in a war zone. I can't imagine my nine-year-old son in that environment.
At the time, you hear gunfire. No-one got hit and no-one died, so you're back in the game. It doesn't change anymore.
When he was nine years old, his parents had separated and his father was living in London while still taking care of the family.
The move of the rest of the family to the UK was supposed to be a new beginning. It wasn't easy from the beginning.
All of your friends are in Jamaica, so you don't want to leave. He says he was upset at the time because he didn't want to leave them.
It's still better than fretting about getting shot by a stray bullet when you're an immigrant.
The other kids at school picked on him because of his Jamaican accent.
A reference to the boxer from the movie that still endures is what inspired his nickname, 'Rocky'.
Things would take a turn for the worse soon.
The Johnsons and the Burger Bars were places where there was a lot of gang activity.
There was constant violence between the two sides.
I became involved from school. You go to the same school as the gang members, and you're in the same neighborhood.
The older guys, the younger brothers, all at the same school, and you get used to hanging around with them.
When he heard of his father's death, he was 13 years old. He says it was a turning point in his life.
He says he had a shorter temper and was more angry.
I regret a few things that I did during this time. It's difficult to believe that I did it. I don't want to talk about it.
I have been in life threatening situations, but I wouldn't say I was afraid for my life. All gangs do the same thing. Drugs were sold and there were attacks.
I was arrested for fighting and having a knife. My mother would go to the police station to get me out.
I knew what I was doing was hurting her, but I kept doing it because my friends were doing it.
Your brain is so focused at the time that you think this is your world. It's not possible to see outside of it.
At the age of 17, while walking to the bus stop with his mother, she spotted a gym above a DVD store that offered training in mixed martial arts.
The man joined the group. He didn't know anything about MMA. The idea of a fair fight was alien to him because his perception of fighting was skewed by gang culture.
I used to think that fighting was not weird, but I wouldn't have a fair fight with someone.
The gangs are more likely to stab you. That was the way of thinking.
He was told by his coaches that he had a talent.
He achieved more after getting a positive reaction from his mother.
"I could see my mum was proud of me, when I was winning awards, and that's what kept me at it," he said.
If you do something bad in a gang, everyone supports you, so I thought I might as well do good.
I wanted to enjoy my life and not have to worry about people trying to stab me. I trained at 17 and didn't look back.
After making his amateur debut at the age of 18, he won by submission and went on to make his professional debut a year later.
He signed with the UFC at the age of 23.
He hasn't lost since he was defeated by Kamaru Usman seven years ago.
He will become Britain's first champion in two years if he wins.
When talking about his story, the man has always been reserved. He has never embraced the "gangster" narrative.
He wants to help other people who are looking for change. He believes sport could have saved his life.
He didn't want to be seen as a mobster.
I want to be a better person than my story was. The more I succeed, the more I want to help others. I want people to know that it's not where you start but where you finish.
I've lost friends to knife crime in the UK, so if I can go back and help someone, I'll do that.
He went to prison and was stabbed to death. Most of them are still doing what they're doing despite some of them making good and work.
Without MMA, I would either be dead or in prison.
I'm very happy." It's not just me but my family as well. My mother would be sad that her husband and son had died.
I knew I could be better, but I didn't know how to. I didn't know how to succeed because I didn't have a plan.
It shows everyone else what's possible if I do it.