Double ONE world champion Christian Lee is gearing up for a return to action later this year. It has taken him to Thailand, where he is currently training at Superbon Training Camp.The famed training facility in Bangkok welcomed the reigning ONE lightweight and welterweight MMA king in an Instagram post, which shows Lee working on his striking, doing pad work while aided by coaches in the camp."Welcome @christianleemma — grateful to have you training with us.💥🥊," the camp wrote on its post. View this post on Instagram Instagram PostChristian Lee, who represents Prodigy Training Center, is looking to ramp up his ONE Championship campaign after going through a self-imposed, two-year hiatus for personal reasons, including mourning the untimely passing of younger sister and fellow ONE fighter Victoria Lee in December 2022.He broke his break from competition in December last year to defend the welterweight MMA belt against undefeated Turkish ace Alibeg Rasulov.'The Warrior' showed little effects of the long break he had, taking the fight to his Dagestani opponent right at the onset. Unfortunately, he accidentally poked Rasulov's eye in the second round of their title showdown.Rasulov was checked on by the ringside doctor and given time to gather himself but was eventually ruled unable to continue after, rendering the match a no-contest.Christian Lee runs it back against Alibeg Rasulov at ONE 173Christian Lee reengages with Alibeg Rasulov on Nov. 16 at the ONE 173: Superbon vs. Noiri, defending this time around the ONE lightweight MMA world title.Lee-Rasulov II was recently added to be part of the tentpole event which will emanate from the Ariake Arena in Tokyo, Japan. The live on-ground show will mark the second event for ONE Championship in the 'Land of the Rising Sun' for 2025.Apart from Christian Lee's title defense, also added to ONE 173 is the all-Thai legend showdown between Rodtang Jitmunagnon and Nong-O Hama for the vacant flyweight Muay Thai world title.The showdown for the inaugural atomweight Muay Thai championship belt between Nadaka of Japan and Numsurin Chor Ketwina has been added, too, as well as the featherweight kickboxing bout between Marat Grigorian of Armenia and ONE-debuting Rukiya Anpo of Japan.With the additions, ONE 173 now features six world title matches, headlined by the unification battle between Thai superstar and featherweight kickboxing king Superbon and interim champ Masaaki Noiri.For more information on ONE 173, follow Sportskeeda MMA and ONE Championship.