"Not only did you take her precious right to life but you deprived her family of a daughter and a sister," Justice Hollingworth said.
"Her death left an enormous hole in their lives... Why did you do these appalling things?"
Justice Hollingworth said the horrific treatment of Maasarwe's body — after she had been killed by Herrmann — was a "significant aggravating feature" of his offending.
"Treating her body in this way showed utter contempt for her dignity," she said.
Justice Hollingworth told the court Maasarwe was "physically small, unsuspecting and alone".
"She had no opportunity to flee or defend herself," she said.
"You quickly subjected her to a savage attack with a crude weapon until she was unconscious.
"You dragged her off the footpath to a position of cover where you raped her...you struck her with the clear intention of killing her not merely injuring.
"Women should be free to walk the streets alone without the fear of being violently attacked by strangers."
Herrmann hit Maasarwe over the head with a metal pole, knocking her unconscious, before dragging her body behind a small hedge and raping her.
He hit her another 12 times with the pipe — causing her to die from traumatic head injuries — before covering her with the flammable spray WD-40 and setting her body alight.
Her final words to him as he attacked her were: "You piece of sh*t."
Codey Herrmann was dressed in a blue T-shirt, jeans and sneakers, refusing to look up during the majority of his sentencing.
The court heard Herrmann had been subject to "extreme physical and emotional deprivation" which started less than six months after his birth in September 1998.
"By your first birthday, your mother had abandoned you to a relative whose own children had been taken by court order," Justice Hollingworth told the court.
"About six months later, you were taken into care and hospitalised with scabies."
Hermann and his sister were later hospitalised again as toddlers with "rotten teeth, digestive problems and delayed developmental milestones".
When Herrmann was 3 he was placed into foster care in Perth, a home he stayed in until he turned 18.
The court heard after his relationship broke down with his foster mother — due to his drug use — Herrmann moved to Melbourne where he briefly lived in youth housing before becoming homeless.
The court heard Herrmann had broken up with his girlfriend a year before Maasarwe's rape and murder and the month before the crime he had attempted suicide.
Herrmann had been squatting in an abandoned, condemned house in Melbourne when he committed the crime and had been feeding himself by shoplifting from supermarkets.
Herrmann's life outside of jail was so difficult, the court heard, that the 21-year-old had told his lawyers "a safe place to sleep, a hot shower and meals three times a day was much better than living on the streets".
"That's a rather bleak reflection of the circumstances you were previously living in," Justice Hollingworth told the court.
Prosecutor Patrick Bourke had asked the Victorian Supreme Court to jail the killer for life over what he called one of Australia's most "vicious" and "depraved" crimes.
During a plea hearing earlier this month, Bourke had to hold back tears as he read through emotional victim impact statements from Maasarwe's family.
"I can't imagine the horror she felt when she saw Codey Herrmann's face," her sister Ruba told the court through her statement.
"Codey Herrmann, you have taken one life but you have broken many more hearts."
Maasarwe's mother Kittam said her killer had "destroyed a beautiful girl".
"When I speak about Aiia, I am overwhelmed by sadness," she said.
"You cannot imagine what happened to me after her death. She was my daughter and friend. I was in touch with her every day. She used to tell me always, 'I miss you so much Mum. When I see you again I will hug you and kiss you'."
Maasarwe's other sister Noor said her sibling was the best person she knew.
"She was always smiling and full of energy. As Mother Teresa once said, 'Some people come into our life as blessings and some people come into our life as lessons'. Aiia just happened to be both."
Herrmann's lawyer Tim Marsh believes his client should receive some leniency.
He told the court he had "no explanation" for Herrmann's actions but explained how a difficult upbringing had led to a moment of "rage" on January 16.
"I want to humanise him," Marsh told the court on October 1.
