Kevin Kennedy's death in a roadside bomb in Afghanistan shook his older brother, Michael, to his core.

Kevin had followed Michael into the Canadian Forces; two years younger, he had enlisted after his older brother did. He even admitted his older brother was his inspiration.

So Kevin Kennedy's death in 2007 changed Michael's life forever — and eventually led him to take up arms against the Islamic State in Syria and Iraq (ISIS) this year.

Kennedy — the 32-year-old Navy veteran from Newfoundland and Labrador who was detained overseas last month — spoke exclusively to CBC News on Friday night, recounting his fight against the ISIS and what led him there.

"I would say just to finish something that my brother started when he went over there," Kennedy said from his mother's home in St. Vincent's, N.L., where he returned Wednesday.

"My brother had a pure heart and he had good intentions and he just wanted to help people … and I guess that was a big part of it."

'My inspiration'

Kennedy travelled to Iraq on June 1, less than three months after he signed his release papers from the Royal Canadian Navy. His detention by Iraqi Kurdish authorities in late November brought his story into the public eye.

During his six-month stint in the Middle East, he said he fought alongside the Peshmerga military forces, the YPG militia in Syria and the Sinjar Resistance Units.

Michael Kennedy poses for a photo in Sinjar, Iraq. (Submitted by Michael Kennedy)

After the Peshmerga, where he worked to train fighters in first aid, Michael moved to a "direct assault unit" in the YPG, which was filled with Western soldiers and where it was easier to get onto the front lines.

He said he played a part in an operation south of Sinjar, in Northern Iraq. He called his unit "very effective."

"I could feel Kevin with me in what I did," Kennedy said. "Kevin was also my inspiration as I was there. Like I was early on, when Kevin followed me into the military."

It was not always so easy; Kennedy admits he was struck with guilt for years following Kevin's death.

"It's a hard pill to swallow knowing that my little brother died. It molded my life after his death. And changed my outlook on my life," he explained.

Michael Kennedy poses for a photo with a wreath laid in memory of his brother. (Submitted by Michael Kennedy)

"Kevin never got to come home and experience life at home after deployment. You know, experience home and just being around family and friends again."

The pair were "very much alike, in most ways," Kennedy said.

Kevin was a joker with a big heart who was very kind to his friends; Michael was more the quiet one.

Kevin died just two months into his deployment in Afghanistan. But that never caused Kennedy to question his decision to go back to the Middle East. Leaving his mother behind in Newfoundland, however, weighed on his mind.

"I thought about my mom back at home," he said. "I always remember how my mother talked about the phone call that she got from the Canadian military when my brother had died.

"I tried not to let it impact the way I operated over there."

Michael Kennedy, middle, sits at a military position near Sinjar, Iraq. Kennedy says this position was completely destroyed by a mortar, which sent rocks and debris flying all over his soldiers. (Submitted by Michael Kennedy)

'Living on another planet'

Kennedy said being over there was like "living on another planet."

Life with the militia groups was "very primitive," he said, sometimes lacking food and often times lacking sleep. Local recruits were typically young, inexperienced men. One of his colleagues, American Michael Israel, was killed in an airstrike, he said.

Still, Kennedy isn't ruling out going back.

"Part of me still wants to be over there," he said, in part because some of his colleagues are still detained by Iraqi Kurdish authorities.

Kay Kennedy is shown with her son Michael. (Facebook)

But his group, imprisoned after crossing a Kurdistan Democratic Party checkpoint with other fighters who had let their visas expire, had also planned to reunite in the new year to continue their mission.

"I thought about going back after Christmas, but I guess the way things ended, I guess a lot of the guys are just going to go home and … try to move forward with their lives."

Kennedy was released after eight days in prison, he said, after a visit from Canadian diplomatic officials. His possessions were seized.

But he said he does not regret his experience.

"We just went over and we fought against evil," Kennedy said. "I just wanted to be able to be one of the guys who could say, you know, I went over there with all this in my heart."