Another American fighter with the international troops also died.
They also claimed many casualties on the other side.
Former soldier and No Duff Charitable Trust co-founder Aaron Wood today said it was only a matter of time before a New Zealander was killed in the fierce fighting.
"If anything, it's surprising it hasn't happened sooner, and more often," said Wood who likened the fighting there to "every bad nightmare story that came out of the eastern front circa 1944/45".
"When people engage in that, you're counting the days," he said.
"While it is obviously very sad that he was killed, he knew what he was doing. I don't mean to sound cliched or callous, it's more of a pragmatic approach.
"He would've known the risks and had been there a while... and quickly figured out whether or not it was for him … and the fact that he stayed, he was comfortable with it."
Ukrainian President Volodymyr Zelensky announced the formation of the International Legion for the Territorial Defense of Ukraine on February 27 which called for foreign volunteers to join the fight against Russia under the Ukraine flag.
Within 10 days, it had reportedly received 20,000 requests to sign-up from people across more than 50 countries.
Wood has been in touch with several former NZDF personnel who have answered Ukraine's global call for help.
He says it would total around 100 people, with some being there for a brief period, others returning for multiple trips, and a few who have been there for the duration of the war.
The number at "the tip of the spear" like Abelen numbered "in the very low tens", Wood said, along with doctors, medics, and others in support.
Each individual has their own reasons for going, Wood said, ranging from those wanting to stand up against Russian aggression in what they see as a "righteous fight", to those servicepeople who trained for years but maybe never had the chance to put their skills or mettle into action, and the many "at a loss" after leaving the NZDF and struggle with the transition to civvy-street.
Earlier this month, the government announced it was sending a further 120 NZDF personnel to Britain to help train Ukraine soldiers as part of an international effort to help Ukraine continue to defend itself against Russia's illegal war.
It followed a completed deployment of 30 NZDF personnel in May to train Ukrainian military personnel in operating artillery.
"New Zealand has been clear that we will continue to answer the call of Ukraine for practical support as they defend their homeland and people against Russia's unjustified invasion," Prime Minister Jacinda Ardern said on August 15.
"We know that one of the highest priorities for Ukraine right now, is to train its soldiers, and New Zealand is proud to stand in solidarity alongside a number of other countries to answer that call."