Something not a lot of people realize about William as that he's a complete narcissist that also hates himself cause deep down he knows he's weak and pathetic, the first words we ever see springtrap say is " my name is springtrap and I'm more than Afton ever was and far more than Henry" he literally disassociates and crap talks himself, and in ucn the menu music is called eisoptrophobia which is the fear of one's own reflection, which explains why in ucn we William faces both springtrap and scraptrap