|Born||12 June 1991|
Maebashi, Gunma, Japan
|Professional wrestling career|
|Billed height||188 cm (6 ft 2 in)|
|Billed weight||110 kg (243 lb)|
|Trained by||Yuji Nagata|
|Debut||January 3, 2017|
Tomoyuki Oka (岡 倫之, Oka Tomoyuki, born June 12, 1991 in Maebashi, Gunma, Japan) is a Japanese professional wrestler trained by and signed to New Japan Pro-Wrestling (NJPW) under the ring name Great-O-Khan (グレート-O-カーン, Gurēto-Ō-Kān).
Oka excelled in amateur wrestling while in school, winning the All Japan Wrestling Championship in the 120 kg Freestyle class in 2012. Oka met Takaaki Kidani, president of Bushiroad in 2013, and was signed to New Japan Pro-Wrestling (NJPW) shortly after, but didn't begin training until 2015 as he was still in university at the time. Oka is an avid anime fan, citing Milky Holmes as his favourite anime. In the past, Oka has also competed in judo, karate, sambo, kickboxing, pankration, jiu-jitsu and mixed-martial arts.
Oka began training with New Japan Pro-Wrestling (NJPW) in 2015, and made his in-ring debut on February 25, 2016, wrestling fellow rookie Katsuya Kitamura to a draw in a dark match at Lion's Gate Project 1. Oka and Kitamura wrestled to another draw in a dark match on September 1 at Lion's Gate Project 3. Oka made his televised debut on January 3, 2017, losing to his trainer Yuji Nagata. Oka once again lost to Nagata on January 27, January 31, and February 2. On February 9, Oka, Yoshitatsu and Henare were defeated by Nagata, Hirai Kawato and Jyushin Thunder Liger. Oka's first victory came on February 21, when he defeated Henare via referee stoppage after Henare suffered an ankle injury during their match. On April 13 at Lion's Gate Project 4, he teamed with his trainer Yuji Nagata to defeat Katsuya Kitamura and Manabu Nakanishi. On July 22, he and Nagata defeated Kitamura and Hiroshi Tanahashi. Oka then formed a tag team named "Monster Rage" with Kitamura. From October 12 to December 21, Oka took part in the 2017 Young Lion Cup, where he finished third with a record of three wins and two losses. Oka and Kitamura made their debuts in All Japan Pro Wrestling (AJPW) on July 5, 2017, losing to Wild Burning (Jun Akiyama and Takao Omori).
On June 30, 2018, Oka debuted a new look and ring name, Great-O-Kharn. He defeated Shota Umino with a new finisher, a Mongolian chop delivered from the second turnbuckle. Great O-Kharn started his excursion in the United Kingdom with New Japan affiliate Revolution Pro Wrestling and has started with 3 impressive wins and has since reinvented his finisher into a Crossbow submission. At Revolution Pro Wrestling's Summer Sizzler O-Kharn defeated American Superstar Shane Strickland and continued his winning streak into the Rev Pro tapings. On October 13, 2019, The Great O-Kharn teamed with Rampage Brown to win the RPW Tag Titles. A month later, on November 24, O-Kharn and Brown unified the RPW Tag Titles with the SWE Tag Titles when they defeated The Moonlight Express.
On October 16, 2020, O-Kharn, now going by the slightly modified ring name Great-O-Khan, returned to NJPW during G1 Climax 30, helping Will Ospreay defeat Kazuchika Okada. He joined Ospreay and his girlfriend, Bea Priestley, in a new faction, The Empire. In November 2020, O-Khan and new member of The Empire, Jeff Cobb would enter World Tag League where they finished with a record of 5 wins and 4 losses. The faction would rename itself United Empire in January 2021. O-Khan would wrestle and lose to Hiroshi Tanahashi at Wrestle Kingdom 15. After Tanahashi defeated Shingo Takagi in the main event of The New Beginning in Nagoya to win the NEVER Openweight Championship, O-Khan would attack Tanahashi and then issue a challenge for the following months Castle Attack event. At Castle Attack, Tanahashi would once again defeat O-Khan. In March 2021, O-Khan entered the New Japan Cup for the first time, where he defeated Tetsuya Naito in the first round, but lost to Toru Yano in the second round. Following this O-Khan feuded with Tetsuya Naito culminating in a singles match at the 26th April Road To Wrestling Dontaku event. O-Kahn was defeated by Naito in this match. In September O-Kahn was announced as a participant in G1 Climax 31, his first appearance in the tournament. He finished the tournament with a record of four wins and five defeats, for a total of 8 points. At Power Struggle, O-Khan unsuccessfully challenged Toru Yano in an amateur rules match for the 2021 KOPW provisional championship. O-Khan's 2021 concluded with World Tag League, teaming with Aaron Heanre. The team finished with a score of fourteen points, seven wins and four losses.