Regian Eersel has left the door open for a potential transition to MMA down the line.Eersel went 7-0 and won the lightweight kickboxing world title before looking to become a two-sport world champion. ‘The Immortal’ continued his ONE Championship domination at ONE on Prime Video 3 last week by becoming the inaugural lightweight Muay Thai world champion.It wasn’t easy, but Eersel secured a split decision win against Sinsamut Klinmee to claim a second title with the promotion. During the ONE on Prime Video 3 post-fight interview, ‘The Immortal’ was asked about fighting in MMA next and had this to say:“It's not a goal. But I never say never, and I leave it up to ONE Championship and that's it, man. I have an open future, I'm 29 now so I still have a couple of years left. So let's see what the future brings.”Eersel’s ability to win belts in kickboxing and Muay Thai was impressive, but becoming a three-sport world champion with ONE would launch him into superstardom amongst combat sports fans.The striking of ‘The Immortal’ would transition beautifully to MMA, but his grappling could leave holes for other fighters to exploit.Beyond Kickboxing@Beyond_KickRegian Eersel has done it!The ONE Kickboxing Champion conquers his second sport, and wins a technical fight against Sinsamut to capture the inaugural ONE Lightweight Muay Thai Championship!#ONEonPrimeVideo311524Regian Eersel has done it!The ONE Kickboxing Champion conquers his second sport, and wins a technical fight against Sinsamut to capture the inaugural ONE Lightweight Muay Thai Championship!#ONEonPrimeVideo3 https://t.co/yKzGDRWZRQRegian Eersel posts list of impressive accomplishments on InstagramRegian Eersel has conquered every challenge put in front of him with ONE Championship. Although non-ONE fans might not know his name, the legacy he is creating with the promotion is unbelievable.'The Immortal’ recently posted his accomplishments on Instagram, writing:“The first one that fought the first Kickboxing match in One Championship. The first Lightweight Kickboxing World Champion of One Championship. The first Lightweight Muay Thai World Champion of One Championship. The first 2 sport Surinamese World Champion of One Championship. 20 Fight Win Streak. 7 Years Undefeated. This one is for the history books. Remember the name. The journey has just begun.” View this post on Instagram Instagram PostRegian Eersel also mentioned during the post-fight interview that a return in December is possible. It’s unknown what sport he will compete in and who it might be against, but ‘The Immortal’ has proven to be a formidable opponent for anyone at any time.