A SELF-confessed sex demon who raped an unconscious 14-year-old girl chose the most horrible way to try to dispose of his victim when he poured petrol over her stricken body and set her alight, a judge said today.

Supreme Court Justice Paul Coghlan said Michael Hermogenes, told police "self preservation'' was behind his attempt to murder the teenager and it was difficult to think of a worse case.

Justice Coghlan said Hermogenes had caused horrific lifelong injuries to the girl, who had trusted him and called him "brother'' in Filipino.

Justice Coghlan jailed Hermogenes for 21 years with a 16 year minimum.

The judge said the church youth leader arranged through an internet chat site to go the victim's home, calling her school and pretending to be her father before saying she would not attend that day.

Hermogenes purchased two four packs of mixed alcoholic drinks and two shot glasses and when he got to the house he plied the girl with alcohol and took revealing photographs of her.

The judge said he attacked the teenager, trying to strangle her with her school stockings and when she was unconscious he then raped her.

Hermogenes dragged her, naked and unconscious, into a bathroom and placed her body face down on the floor and went to buy petrol from a service station.

"Knowing she was unconscious, you left the house and went to buy petrol, that is, you had given thought to what you were going to do,'' Justice Coghlan said.

"You were not prepared to leave anything to chance, so you purchased a box of matches. Your motive was to cover up what you had done, including the rape of your unconscious victim.

"You piled clothes on top of her body and then poured the petrol on top of her and around the general area of the second level of the house. You also placed some deodorant cans from your car near her body.”

The judge said Hermogenes knew she was still alive, telling police “her back was moving up and down”.

Justice Coghlan said that as he set fire to the house he also set fire to his pants, which had been splashed with petrol and he ran outside and rolled around in the grass, before escaping..

A man who was passing noticed the smoke and called Triple Zero and if it had not been for his intervention the teenager would have certainly died.

"When asked why you had attempted to murder her and set the house alight you said it was due to self preservation,'' Justice Coghlan said.

"And when you were asked why you sexually assaulted her you responded 'I can’t give a reason. Sexual demons. I was possessed and in a drunken state'.''

The day after he tried to kill the girl Hermogenes went to a church meeting where prayers were being said for her.

Justice Coghlan said Hermogenes told police his recollection of what happened when he went to the girl’s bedroom was “blurry” because of the amount of alcohol he consumed but there was no doubt about his motives.

"I am satisfied that you set up this meeting fully meaning to take sexual advantage of her and that was a major reason for taking the alcohol.”

"You admitted to a psychologist that you were sexually attracted to her.''

Hermogenes, 25, of Hoppers Crossing, pleaded guilty to attempted murder, rape, indecent assault, producing child pornography, arson and theft.

As Justice Coghlan read out his sentence Hermogenes' mother wept in the public benches and was comforted by family members.

The judge said the girl had full thickness burns to 50 per cent of her body and spent a year in hospital.

He detailed a massive catalogue of injuries that included having part of a foot amputated, infection that led to loss of skin grafts, bleeding from gastric ulcers, a disorder relating to blood clotting that required multiple transfusions, and kidney failure requiring readmission to the Intensive Care Unit.

The teenager will never be able to drive, has suffered severe damage to her vocal chords and has two sets of pressure garments which she needs to wear for 22 to 23 hours a day and requires a silicone dressing to be worn over all raised scar areas.

"She will suffer from them for the rest of her life in the most profound way and will need daily care. Her victim impact statement which was read to the Court was moving,'' Justice Coghlan said.

The total damage to the teenager's home was over $110,000 and her family had suffered financial hardship because of the crime.

In a separate incident Hermogenes took advantage of a friend after a birthday party, taking revealing photographs of her as she lay sleeping and touching and kissing her buttocks.

For more on the church leader rapist Michael Tuano Hermogenes, who has been jailed for 21 years go to the Herald Sun.