Judge Shani Barnes, sitting at Lewes Crown Court, ruled that despite the severity of his crimes he must not be publicly identified.
The boy had been taken to Spain by his mother when he was aged three, where she led an “unconventional lifestyle” before she brought him back to Brighton and abandoned him.
Judge Barnes said she hoped he could get over his anger at the world while behind bars.
She told the boy: “I understand that life has been very difficult for you.
“You are so young and I am determined you will have another opportunity to take responsibility for your actions.”When he kills someone - as he almost certainly will - I hope this foolish woman is stripped of her role and sentenced to what he should have got.