Tina Sahin spoke at his killer's sentence hearing in the NSW Supreme Court on Tuesday, describing her father as a "proud Kurnai man" whose love radiated around his family.

"Do you know what it's like to experience cultural torments while trying to bring your father's body back home to country?" Ms Sahin said.

"So his spirit may journey to the dreaming and finally be at ease.

"I do".

Warren Anthony Scott, 38, stabbed Edward "Eddie" Carter, in an Eden home in April 2019.

"He was only 49 years young when he died."

Scott was found not guilty of murder but guilty of manslaughter due to his underlying mental illness during the "drawn-out" attack.

"Warren Scott's choices to not be responsible or accountable for his own mental health has changed our family forever," she said.

"To think that the only way a mentally ill person can be forced into proper treatment is by committing a tragic offence."

Ms Sahin detailed how the pair were "just getting to the good father-daughter part of life," how they would sit together in silence "absolutely happy and content with each other's presence".

Since his death she suffers numerous panic attacks and has been diagnosed with PTSD, unable to work so overwhelmed by grief.

"Acknowledging the cruel and violent nature of the attack is to acknowledge dad's suffering in his final moments, it truly breaks my heart," she said.

"Injuries suggest he never stood a chance. Every time I close my eyes I can only imagine how scared Dad would have been."

Justice Natalie Adams said the offence constituted manslaughter due to Scott's paranoid schizophrenia at the time, which he was untreated for due to his binge drinking.

"Mr Scott has a mental illness but he knows when he drinks he stops taking his medication and there can be a relapse," Justice Adams said.

She said it was troubling that Scott had been on an intensive corrections order at the time of the stabbing for a less serious but "similar style assault" on his mother.

Prosecutor Nerissa Keay submitted Scott declined to take advantage of a lot of help that was available to him.

His prospects for rehabilitation depend on his sobriety and hopefully, the lengthy time in detention would reset ingrained habits, the court was told.

"Will abstinence be enough or will muscle memory take over?" Justice Adams said.

She also questioned findings of remorse, given the "flat" and "emotionless" evidence Scott gave during his trial.

But this could partly be explained by his strong medication and low intellectual functioning, she said.

The sustained attack on the unarmed Mr Carter occurred at Scott's mother's home after the three were drinking together and listening to music.

Scott first lunged at his mother with a large kitchen knife, but after she fled he kept Mr Carter hostage.

His trial was told an "emotionless" Scott was seen holding the blade right between his victim's eyes, before later saying he would watch him "bleed out".

Justice Adams is due to sentence Scott on December 15.

Australian Associated Press