Rob245

Answer: Alex is not the typical one dimensional slasher serial killer, but rather a complex individual with conflicting motivations. The lipstick is a symbol that he is portraying the hurtful people from his past even as he kills them.

Answer: The film doesn't provide an answer (which I think is a good thing). My interpretation is that Alex has somehow absorbed his sister's spirit, symbolically (not literally), and is avenging her death *as* Robin, in a way. Her name is his last word before he dies. A scene was shot but cut which revealed that Robin and Alex were twins. That scene was added back to the television edit of Prom Night.