Over the course of six years, Demetrious Johnson laid waste to the UFC's flyweight division.
Named its inaugural champion, Johnson went on to set a world-record 11 consecutive title defences during an unprecedented reign of dominance that has him pegged as one of the pound-for-pound greatest mixed martial artists in history.
After conquering that mountain, 'Mighty Mouse' is now preparing to take his first step towards the summit of another of the sport's highest peaks, after his ground-breaking 'trade' to the booming, Asia-based ONE Championship.
The 32-year-old will make his promotional debut at ONE: A New Era in Tokyo on Sunday, in what will seem a foreign and somewhat new experience, but not for the reasons you may expect.
For the first time in his decorated tenure at the top, Johnson will make the walk to cage without longtime coach, friend and mentor Matt Hume.
"I can't remember the last time he wasn't there," said Johnson. "He's been with me my entire professional career, even a few amateur fights."
Hume is considered the mastermind behind Johnson's progression into one of the most complete fighters in the sport's history.
But due to the conflict of interest that arises from his position as a vice president of operations and matchmaker with ONE, he'll be watching from a distance, when his star pupil gets down to business against local Yuya Wakamatsu in the quarter-final of ONE's Flyweight Grand Prix.
"We've already accomplished what no other MMA athlete has ever accomplished, but it will be interesting."
Another accomplice who'll be so close, yet so far, will be Johnson's closest training partner and "brother from another mother" Bibiano Fernandes. A ONE stalwart, Fernandes will also be in action at the iconic Ryogoku Kokugikan Arena, hoping to get his hands back on the bantamweight belt he lost late last year, after a staggering nine-straight defences.
Given his pedigree and the long list of victims in his wake, Johnson could be forgiven for expecting to walk immediately into contention for another title.
But he wants nothing handed to him on a silver platter and he's more than willing to earn his chance, just like everybody else.
"Obviously, I could've come in here and said I'm not coming unless I get a title shot, because I've been a champion and that's all I know about - being a champion," said Johnson.
"But for me, it makes sense. I'm going to work my butt off to see if I can get a title shot - earn it the right way, instead of trying to politic my way to a title shot."
Wakamatsu will be his first hurdle on the journey to a challenge for Adriano Moraes' flyweight strap.
The 24-year-old's chances have been widely dismissed by the MMA world, but the former Pancrase world champion isn't fased by either the bright lights or his more famous opponent.
"He's a lot smaller than I expected," said Wakamastu, after first coming face-to-face with Johnson at the pre-fight press conference on Thursday. "I think he was intimidated by me."
Diminutive, even by flyweight standards, for veteran Johnson, it's all business as usual. New stage, same show.
"Just training, as I have for all of my fights," he said. "It's about me being the best athlete that I can be when it comes to fight night."
"I'm looking to go out there and push the pace, and hopefully get the finish… I won't disappoint you guys."