The brother of a British champion mixed martial artist (MMA) has been detained indefinitely for stabbing him to death as he celebrated his 30th birthday.
Dwight Freeman, 19, killed Jahreau Shepherd, nicknamed The Nightmare, at a party in Kennington, south London, on 11 July last year.
Freeman, from Vauxhall, south London, admitted manslaughter by diminished responsibility last month.
At the Old Bailey he was handed a hospital order without limit of time.
Prosecutor Caroline Carberry QC told the court that Mr Shepherd was an "accomplished" MMA fighter who lived with his mother and half-brother, who was known as DJ.
Mr Shepherd acted like a father figure to his younger sibling because he wanted him to "fix up and be better" and stop smoking skunk cannabis, the court was told.
In the six months before the killing, the defendant suffered mood swings and had "terrified" his mother when she woke up to find him staring at her at the foot of the bed.
On the evening of 11 July, Mr Shepherd held a birthday party and barbecue in a park for some 60 guests.
At about 22:00 BST, numerous friends looked on as Freeman, wearing black and with his hood up, carried out a "terrifying, sustained and unprovoked attack with a large knife or knives", Ms Carberry said.
The weapons were variously described by eyewitnesses as a machete, Samurai swords and a zombie knife.
'I love you'
One eyewitness heard Mr Shepherd appear to tell off the defendant who then hit him several times with a machete.
Mr Shepherd was heard to say: "I love you. What are you doing?"
He held his hands up as he appealed to his brother, saying: "I'm sorry, I'm sorry. Don't do this," the court was told.
Mr Shepherd suffered 13 wounds including to his back, shoulder, thigh, face and stomach, with the two fatal injuries being about 19cm (7.5 in) deep.
Freeman fled the scene following the attack, disguised his appearance and went on the run in the West Country. He was finally arrested in Cornwall.
The court heard that since he had been in custody, psychiatrists diagnosed him with paranoid schizophrenia.
As well as admitting killing his brother, the 19-year-old previously pleaded guilty to wounding 26-year-old Joel Belgrave with intent.
Mr Belgrave suffered a punctured lung after he was stabbed as he tried to stop the attack.
Judge Richard Marks QC told Freeman: "Such was the degree of violence used by you on your brother, one can only conclude your intention was to kill him."
He added that it was "obviously a very tragic case".