So much of the Silent Hill franchise is about the sexualization and hatred of women, with the male monsters (that act as guides for the main characters) mutilating and raping female monsters as an expression of the male character’s mindset.
How about an adult woman as the main character for once? A woman who has gone though a lot of hardship in her life and has a deep, subconscious hatred of men. She doesn’t want to acknowledge these feelings however because she has a young son, and the thought that he will one day be a man too makes her uncomfortable, so she has to pretend she has no problem with men, both for his and her own sake.
That is why her “Pyramidhead” is a towering female monster with scars on her abdomen like she ripped a baby out once. She attacks male monsters along the way, mutilates their crotches, rapes them with their own phallic weapons, and strangles them with her metal loop. She never attacks the main character unless the main character attacks her, and even appears to clear the way for her on a few occasions, guiding her through the game.
It sounds harsh, but just think about what happens in the Silent Hill games.
Pyramid-head is a representation of guilt and destructive feelings towards the player. That is why he constantly attempts to kill the main protagonist and yet appears to help you progress in places- he both wants to kill them as well as make them face reality.
Pyramid-head attacks other monsters because, as his role of guilt, he tries to repress the other monsters that all represent memories or feelings that the player wants suppressed.
While I share your hatred of the sexy nurses being overused... they aren't a sign of hatred toward females but a representation of repressed libido and sexual thought. The series is a great fan of body horror to try and convey a type of gross fascination of the deepest most innermost horrors of the main characters, they continued on in later games and marketing material because marketing execs do not understand their representation.
If there was to be a female pyramid-head she most certainly would NOT be a guide, but a terrible malevolent force desperately trying to kill the main character. Every single creature in silent hill despises the player- because they are the feelings the player character either represses or feel are eating them alive from the inside.
While the character concept is interesting she is lacking the helmet- which is a personal design choice yes, but is poignant for the character of 'guilt' because the inside of it is lined with spikes like an iron maiden, it also obscures vision and makes them walk as if it is a burden. The helmet is a punishment on the character. I feel this is true of all the creatures in silent hill, where a majority, if not all of them do not generally 'stalk' you because their own lives of torment, manifested by the player, are simply too much to bear. The gigantic weapon is also a type of tether, a huge weight he drags along behind him, but he cannot discard because he requires it.
If the female monster was not given restraint and still followed the art style of the games, it would symbolize that your main character feels absolutely no remorse about her feelings and genuinely wishes to mutilate and kill all males, even her son, without apology.
That deconstruction aside however I do like her overall monster's look.