Alleged king hit attacker refused bail

A Sydney teenager is likely to be left with brain damage after allegedly being punched to the ground on New Year's Eve by a man claiming to be a mixed martial artist, a court has heard.

Daniel Christie, 18, is in a critical condition in St Vincent's Hospital after he was punched in the face in Kings Cross during New Year's Eve celebrations.

Doctors believe Mr Christie will probably suffer a serious brain injury if he survives the vicious assault that occurred as he walked through Kings Cross with his brother on Tuesday night.

Mr Christie remained in a critical condition on Thursday and was likely to stay that way for the next 24 hours, a St Vincent's Hospital spokesman told AAP.

The court heard Mr Christie will likely suffer from a considerable brain injury after being punched by his alleged attacker, Shaun McNeil, while shielding two other alleged victims.

Police Prosecutor Sergeant Lisa McEvoy said McNeil, who has a history of violence, was celebrating in the city from 9am on Tuesday and had drunk around eight beers and one glass of wine.

"At the end of his time in town, there's a man on the floor with a fractured skull and suspected brain injury and other people with cut lips," she said.

Sgt McEvoy said the police facts in the case were "horrific".

"This was completely unprovoked," she said.

According to facts tendered in court, McNeil had just left the Punchbowl bar in Kings Cross with his girlfriend when he got into a verbal altercation with two young men and an unidentified boy.

After allegedly telling them he was a mixed martial arts fighter, McNeil struck the boy before punching both of his friends, causing them to fall to the ground, the facts said.

As the boy ran one way, the two men ran down the street and attempted to hide behind Mr Christie, who was then allegedly targeted by McNeil.

"The victim has fallen backward and struck his head on the pavement, causing immediate life-threatening injuries," the facts said.

When Daniel Christie's brother Peter tried to intervene, McNeil then turned on him, allegedly punching him and splitting his lip.

McNeil, 25, faced Parramatta Bail Court via videolink on Wednesday where he cried as he was refused bail.

He has been charged with one count of causing grievous bodily harm to Daniel Christie, one count of assaulting Peter Christie, and two counts of common assault.

Wearing a forensic suit, he said little during his court appearance on Wednesday.

McNeil has several convictions for violence and dishonesty, the court heard.

The court heard McNeil told police he was acting to protect his girlfriend.

His lawyer said the young men tried to sell him drugs.

McNeil was "very sad" when he heard about Mr Christie's life-threatening injuries, the court heard.

Registrar Chris Steptoe refused bail, noting the "current climate" of unprovoked assaults in Sydney.

The alleged assaults occurred on the same street on the late-night strip where teenage king hit victim Thomas Kelly was killed in 2012.

"Mr McNeil does not live in a box," Sgt McEvoy said.

"He is aware of the circumstances surrounding the recent death of a young man, not to mention the few other young men who ended up in hospital (in similar circumstances)."

McNeil will face court again on Monday.

NSW Premier Barry O'Farrell said he was "appalled" at the incident, saying the state government will crackdown on problem venues and problem precincts.

"There's no doubt the Christie family today, like the McEwan family, like the Kelly family, are suffering in ways families should never have to go through," Mr O'Farrell told the ABC Radio on Thursday.

"I don't understand the violence lust or the violence rage that exists out there below the surface."

But he said the number of assaults at Kings Cross had reduced by one third due to a government crackdown in the precinct in the last year.

"That's of no comfort to the Christie family this morning but equally, the slogan being put forward by my opponents - 1am lockouts, 3am shutouts - is of no comfort to someone who was assaulted at 9pm," Mr O'Farrell said.