Early career In 2016 Endy participated in an eight man King of the Ring tournament. Following a flying knee win over Nicky Lopez and a TKO win over Marcel Verhaar, Semeleer faced Robert Siebenheller in the final match of the tournament. He won the fight by a first round knockout.
Enfusion Abu Dhabi Tournament The following year, he was signed with
Enfusion. He achieved a four fight winning streak with the organization, with decision wins over
Bilal Loukili and Regilio van den Ent, as well as KO wins over Hamed Nabil and
Jordan Watson. This earned him a spot in the Enfusion Eight Man Tournament. In the quarter-final bout he scored a third round TKO win over
Diogo Calado, and in the semi-finals a decision win over
Mohamed Khamal. In the finals of the tournament, Endy faced the kickboxing and muay thai legend
Superbon Banchamek. Semeleer won the fight by a unanimous decision, winning the tournament and €100 000 in prize money. Combat Press gave this fight their "Upset of the Year" award.
Enfusion 75kg Champion Semeleer faced
Enfusion Aziz Kallah for the vacant 75 kg World title at Enfusion 73 on 27 October 2018. He won the title by unanimous decision. Two months later, Semeleer participated in the Enfusion -72.5 kg tournament, which was held at Enfusion Live 76 on 7 December 2018. Although he won the quarterfinal bout against
Marouan Toutouh by unanimous decision, he forced to withdraw due to an injury he suffered during the bout. Semeleer attempted to become a two weight world champion when he challenged the reigning 72.5 kg champion
Tayfun Özcan at Enfusion Live 79 on 23 February 2019. Semeleer suffered the first loss of his professional career, dropping a decision to the Dutch-Turkish fighter. Semeleer made his first -75 kg title defense against
Marouan Toutouh at Enfusion 85 on 8 June 2019. He won the fight by unanimous decision. Semeleer faced Davide Armanini in a non-title bout at Enfusion 89 on 26 October 2019. He won the fight by a third-round technical knockout.
Double champion Semeleer once again attempted to capture the 72.5 kg World title at Enfusion 98 on 3 October 2019, as he was booked to face Nordin van Roosmalen. Endy scored an early knockdown in the first round, landing a knee to Nordin's head. He dominated the remaining four rounds as well, and won the fight by a unanimous decision. Semeleer was booked to face the two-time Dutch kickboxing champion Kevin Hessling on 11 September 2021, at the Enfusion's
Nijmegen event. He won the fight by a first-round knockout. Semeleer was scheduled to face
Jay Overmeer for the inaugural
Enfusion World Welterweight (-77kg) Championship at Enfusion #104 on 12 November 2021. He won the fight by unanimous decision.
Glory On 21 April 2022, it was announced that Semeleer had signed with
Glory. Semeleer was expected to make his debut against
Harut Grigorian at
Glory Rivals 1 on 21 May 2022. The event was later postponed, as The Lotto Arena announced that their cooperation with the Antwerp Fight Organisation had been terminated due to various administrative reasons. Semeleer was expected to face
Robin Ciric in the main event of
Glory Rivals 2 on 25 July 2022. Ciric withdrew from the fight in 29 August, after contracting
COVID-19, and was replaced by
Shkodran Veseli. Semeleer won the fight by third-round knockout.
Welterweight champion Semeleer faced the second-ranked Glory welterweight contender
Alim Nabiev for the vacant
Glory Welterweight Championship at
Glory 82 on 19 November 2022. He won the fight by split decision, with three judges scoring the bout 48–47 in his favor, while the remaining two judges scored it 49–46 and 48–47 for Nabiev. Semeleer made his first welterweight title defense against
Murthel Groenhart at
Glory 85 on 29 April 2023. He retained the title by unanimous decision, after knocking Groenhart down several times, with all five judges awarding him a 50–42 scorecard. Semeleer made his second title defense against the #1 ranked Glory welterweight contender
Jay Overmeer at
Glory: Collision 5 on 17 June 2023. He retained the title by unanimous decision. Semeleer made his third
Glory Welterweight Championship defense against Anwar Ouled-Chaib at
Glory 90 on 23 December 2023. He won the fight by a first-round knockout.
Title loss Semeleer made his fourth
Glory Welterweight Championship defense against
Chico Kwasi at
Glory 91 on 27 April 2024. He lost the fight by a second-round technical knockout. Semeleer faced the reigning
Glory Lightweight champion Tyjani Beztati in a welterweight bout at
Glory 93 on 20 July 2024. He lost the fight by unanimous decision. == Championships and accomplishments ==