A judge has ruled murder-accused Michael Waipouri's claim he acted in self-defence can't be considered by a jury.
Waipouri, also known as Michael Davies, is standing trial for the murder and kidnapping of Lance Murphy where closing arguments are being heard on Tuesday.
The 56-year-old's body was found in a field near Wellsford in December 2015, nearly three weeks after he was last seen at a BP service station in Warkworth.
The court heard Mr Murphy was killed after Waipouri repeatedly hit him in the head with a bat and a tree branch on a remote hilltop in Puhoi.
Murphy was handcuffed and had a bag over his head at the time.
Co-accused Steve Gunbie has also pleaded not guilty to kidnapping and helping Davies avoid arrest, after he helped to dispose of Mr Murphy’s body.
Waipouri previously told the court he believed Murphy was a hitman who'd killed 10 people.
He claimed Mr Murphy murdered his own wife and mother-in-law, and Waipouri feared he was next after he "declared war on him".
He said he then killed him after seeing a demon with 10 heads come out of his chest - one for every person Murphy had killed.
During his closing address Crown Prosecutor Gareth Kayes told the jury self-defence is no longer an issue to consider.
"From that you can be well and truly sure that Waipouri is guilty of murder."
The court heard Waipouri used a bat to attack Mr Murphy and when that wasn't sufficient he switched to a tree branch.
"Waipouri didn't stop until Murphy's skull caved in, and he heard him stop breathing."
Mr Kayes told the court even that evidence alone proves his intention was to kill Murphy.
"We know what type of force he used. Waipouri later told police he strikes hard, and strikes for keeps."
Mr Kayes told the jury Waipouri even re-enacted the attack for police.
"He did so with a water bottle - crack, crack, crack - and he said there is no way he was leaving that vicinity without him dead.
"If there's any doubt - and I suggest there isn't… he told police he was hitting him and intending to kill him."
The Crown also spoke about Waipouri's mental state.
"A few times in giving his evidence you may have been troubled by his mental state. But his lawyers are not saying he's insane, or has any insanity defence available to him."
He said a psychiatrist's evidence was that despite Waipouri's paranoia he had no signs or symptoms consistent with mental illness, and wasn't insane at the time of the killing.
With self-defence no longer able to be considered, Waipouri's lawyer John Munro urged the jury to instead return a verdict of manslaughter.
"I'm not asking you to return verdicts of not guilty to murder, we don't have self-defence anymore. But what you now have the ability to do is return a verdict of manslaughter. It's a middle ground and one step lower than murder. If you have any reasonable doubt, you can do that."
Mr Munro told the court Waipouri not once tried to cover up the killing.
"He had the chance to sit back and say nothing, but he didn't deviate from what was said at the very beginning. He maintained that version of events. You may find some solace in that sort of honesty."
He also reminded the jury about the spiritual elements of the case, particularly in reference to the demon Waipuri said he saw coming out of Mr Murphy's chest.
"Keep an open mind about these sorts of things, don't poo-poo them. The spiritual element of this case is well founded, and should be factored into your decision."
The trial continues.