The phantom was indeed real. I stumbled across a magazine article from 1907 that explained a few things. Here is the article.
In 1907, when we were repairing the Palais Garnier, we broke through a wall in the fifth cellar and found a fully furnished apartment. We then later found a male corpse in the third cellar. He had a disfigured(it actually used an asymmetrical) face and on itseft hand was a gold band with the initials C.D. On them. C.D stands for Christine Daač. We identified this man as Erik.
Upon further research I found out that Raoul Vicomte De Changey was real as well. I rest my case. Thank you for reading this.