Kickboxing champion Maksym Kagal died defending Ukraine as part of the controversial Azov unit

• A champion kickboxer, Maksym Kagal, was reportedly killed in battle Friday in Ukraine.
• His coach said in a Facebook post that Kagal died March 25 in Mariupol.

Kickboxing champion Maksym Kagal was killed in battle Friday while defending Ukraine from the ongoing Russian invasion in the city Mariupol.

Kagal, 30, reportedly died as part of the controversial Azov special forces — a battalion of up to 1,500 members that has been frequently characterized by The Guardian, MSNBC, and Al-Jazeera, as a far-right paramilitary group with some fighters who displayed neo-Nazi leanings.

"Unfortunately, the war takes the best," Kagal's combat sports coach Oleh Skyrta said in a Facebook post.

Russia invaded Ukraine on February 24 with Vladimir Putin attempting to justify the aggression because of a goal to "denazify" the country.

In the weeks since, more than 10 million people have been displaced as multiple Ukraine towns and cities have been shelled from Russian aggression. Thousands have died.

Skyrta said Kagal died on March 25 while "defending the city of Mariupol, as part of the Special Destination Squad 'Azov'."

The kickboxing coach then listed Kagal's achievements as the first world champion kickboxer from his gym. He called him "an honest and decent man."

Skyrta finished by remarking: "Rest in peace, brother … we will take revenge on you."

The Azov Special Operations Unit was formed in 2014 as a volunteer militia. It was incorporated into the National Guard later that year.

Though it denies links to neo-Nazism, it has used controversial imagery and symbols linked to Nazism.

A battalion spokesperson even told USA Today in 2015 that up to 20% of its members were Nazis.