If the enemy of my enemy is my friend, and by that logic, my friend’s enemy is my enemy, what does this have to do with McKenzie friends?
Pause before you conjure up and pretend to give some semblance of an intelligent answer, or nod with a knowing, deep, and meaningful expression on your face, hiding the reality that you have no idea, or care particularly.
The original McKenzie friend was Ian Hanger, (later made Queen’s Counsel, and now a mediator in Queensland, Australia) in the case of McKenzie v McKenzie  3 ALL ER 1034, CA. Mr McKenzie was legally aided, but then legal aid was withdrawn. He could not afford legal representation, but Mr Hanger was prepared to go to court as a professional friend of McKenzie: A McKenzie Friend, to sit behind him, suggest advice based on procedure and the law, and to assist generally. The Judge at first instance would not allow this on day one of the trial, and so on day two, there was little point in Mr Hangar being at court.
Mr McKenzie appealed the decision on the basis that he had been denied legal representation. The Court of Appeal agreed and the matter was re-tried.
Thus sprang the principle that a McKenzie friend is someone who can assist a litigant-in-person in court with paperwork, court procedure, and assistance generally.