Here's why:
* Amoral Philanderer: The Phantom, while a brilliant musician and a tragic figure, is also a manipulative and selfish individual who uses his power to control Christine Daaé and other women.
* Ghostly Revenge: The Phantom is killed by Raoul de Chagny, Christine's love interest. He is then dragged down to hell by his own ghost, which he has been keeping alive through a dark pact.
While the Phantom's death and descent to hell are not explicitly shown in the original novel, the imagery of his ghost taking him away reinforces the idea of karmic retribution. The Phantom's amoral behavior and manipulation ultimately lead to his own demise and eternal damnation.
It's worth noting that the musical adaptation of "The Phantom of the Opera" expands upon this theme, with the Phantom's ghost becoming more prominent and the consequences of his actions more apparent.