Gary Smith, 28, was left with facial scarring, both long and short-term memory loss, and now has no sense of smell.
He became depressed after his face was slashed and he suffered a brain haemorrhage, fractured skull and broken jaw following the attack.
The gang was recorded planning the attack by detectives who had bugged defendant Akmol Hussain’s car over an unrelated matter.
They were taped saying they wanted to hit or kill the teacher just because he was the head of religious studies at the Central Foundation School for Girls in Bow, East London.
In one recording Hussain said: ‘He’s mocking Islam and he’s putting doubts in people’s minds . . . How can somebody take a job to teach Islam when they’re not even a Muslim themselves?’