Can somebody tell me why the persian is important the story in the phantom of the opera (le fantome de l'opera frank milani translation)

" The Persian’s actions as both friend and conscience play an important role in The Phantom of the Opera. He attempts to change Erik from a monster into a man by forcing him to promise that he would no longer commit murders and also by reminding Erik that he owes the Persian his life. As the Persian and Raoul are close to drowning in the cellars, the former calls out to the scrap of humanity he has striven to place in Erik’s heart with the hope that previously buried mercy will at last surface: “I saved your life! Remember! You were sentenced to death! But for me, you would be dead now!”[2] Although Erik instead responds to Christine’s pleas to save their lives, he would not have been as receptive had the Persian not been a true friend in the past and a persistent conscience in the present. His influence makes it possible for Christine to bring Erik into the human race at last. "
source : https://thefellowshipoftheking.net/2014/10/26/the-ghosts-conscience-the-persian-in-the-phantom-of-th...