The unbeaten ZFN fighter crosses over from MMA to professional boxing on October 3, facing Ukrainian knockout artist Anatolii An at MK Boxing Center in Yangsan.
“Yangsan Mad Man” is trading the cage for the boxing ring.
Se Hoon Choi (최세훈), one of the more recognizable personalities to emerge from South Korea’s recent MMA scene, is officially set to make his professional boxing debut on Saturday, October 3, at MK Boxing Center in Yangsan, South Gyeongsang Province.
Representing MK Gym, Choi will face Ukrainian boxer Anatolii An (안 아나톨리) of SG Boxing.
For Choi, it isn’t simply another striking match.
After establishing himself as an undefeated professional MMA fighter and testing his hands in professional boxing exhibitions earlier this year, October 3 will mark his first official step into professional boxing.
And he isn’t being given an easy introduction.
An enters the matchup with a 2-0 professional boxing record — with both victories coming by knockout.
From “Yangsan Mad Man” to Professional Fighter
Choi’s route into professional combat sports has been anything but conventional.
Known by his “Yangsan Mad Man” nickname, Choi developed a following through his aggressive personality and willingness to engage before eventually transitioning into professional MMA.
Since then, the personality has increasingly been backed up by results.
Choi is listed at 182 centimeters and competes out of MK Gym, with striking identified as his primary fighting style.
His professional MMA run began at ZFN 2 in December 2024 against Jae Geun Yang. Choi stopped Yang with punches in the opening round.
He followed that performance with a majority-decision victory over Jun Gu Kim at ZFN Origin before returning to his finishing ways against Bum Seok Jang at ZFN 3, scoring another first-round TKO.
Most recently, Choi faced Jae Woong Yoon at ZFN 4 in May. That fight lasted just 99 seconds, with Choi earning a first-round TKO through punches and elbows. Sherdog currently lists his professional MMA record at 4-0 with three victories by knockout or TKO.
That record has made the “Mad Man” persona increasingly difficult to separate from a legitimate combat-sports career.
Now he is testing just how far his striking can go when everything else is taken away.
Boxing Without the Safety Net of MMA
Choi has already given fans a preview of what that transition could look like.
He competed in professional boxing exhibition bouts in February and July 2026, gaining experience under boxing rules before committing to an official professional debut.
But an exhibition is different.
On October 3, there are no kicks, elbows, takedowns or grappling exchanges to create openings.
There are only punches.
For a fighter whose MMA success has largely been built around aggression and striking, that makes this crossover particularly interesting.
Choi has shown considerable finishing power in MMA. Three of his four recorded professional victories have ended by TKO, all three coming in the opening round.
Professional boxing will test whether that power translates when he is standing across from someone whose entire competitive game is built around the same weapons.
Anatolii An Is Not a Showcase Opponent
That is where Anatolii An changes the complexion of the matchup.
The Ukrainian represents SG Boxing and enters with a 2-0 professional record.
Both victories have come by knockout.
For someone making his professional boxing debut, facing an opponent who has yet to hear the final bell as a winner creates an immediate test.
Choi may have considerably more experience dealing with the variables of an MMA fight, but those experiences don’t automatically transfer into advantages inside a boxing ring.
Distance changes.
Defense changes.
The rhythm changes.
Even Choi’s instinct to pressure becomes different when his opponent doesn’t have to worry about a level change, kick or clinch-to-takedown transition.
Against An, every entry potentially becomes a boxing exchange.
And with two knockouts in two professional victories, An has already demonstrated that he can punish mistakes.
Can Choi’s MMA Pressure Translate?
There is little mystery surrounding what has made Choi entertaining in MMA.
He comes forward.
Choi has built much of his reputation around a willingness to exchange and force his opponents into uncomfortable fights. His recent MMA performances have also shown increasingly effective straight punches and an ability to capitalize once an opponent is hurt.
The question is how that approach changes under boxing rules.
In MMA, aggression can force an opponent to think about several threats simultaneously. In boxing, An can focus entirely on Choi’s hands, movement and positioning.
Choi will have to show more than power.
His jab, defensive positioning, head movement and ability to enter without absorbing clean counters could become much more important than they are when competing with a broader MMA arsenal.
But there is another side to that equation.
An also has to deal with someone who is accustomed to physical fights and who has already demonstrated that he isn’t particularly interested in taking a backward step.
If Choi can turn his professional debut into the kind of high-pressure fight that has suited him throughout his MMA career, the difference in professional boxing experience may become less comfortable for the Ukrainian.
A New Test for the “Mad Man”
The October 3 card will also feature an exhibition involving Kyung Hoon Kang and Vadim, adding another crossover element to the event.
But much of the attention will naturally fall on Choi.
His combat-sports trajectory has moved quickly. From his professional MMA debut in December 2024 to an unbeaten run through ZFN, Choi has gone from an unconventional prospect with a memorable nickname to a fighter producing legitimate results.
Now comes a completely different measurement of his striking.
Se Hoon Choi vs. Anatolii An takes place Saturday, October 3, 2026, at MK Boxing Center in Yangsan, South Gyeongsang Province.
For An, it is an opportunity to extend a perfect knockout start to his professional career.
For Choi, it is the beginning of another one.
The cage made the “Yangsan Mad Man” known.
On October 3, we’ll find out what he looks like when there is nowhere to go but forward inside the ropes.
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