What are some unusual characters in The Princess Bride?

Westley might be considered an unusual character.  While
his mythology and background could be seen as a typical hero, Westley really is not the
normal hero.  He endures insults from Buttercup and starts off in the lowest rung of the
social order.  While he experiences the "derring- do" of swashbuckling ends, he does so
rather inadvertently.  It's out of being kidnapped that he ends up living the life of
the Dread Pirate.  Westley is not conscious of being a hero or a heroic figure.  This is
what makes him unusual.  We look to him as a figure or leading protagonist, but he is
not really one who sees himself in such a manner.  Part of why he is like this is that
Westley never fully embraces his love for Buttercup.  This makes him unusual in the
narrative.  Traditionally, the reader is accustomed to a character who is able to
embrace their "destiny" to love the damsel.  Westley is unusual because of his
divergence from this configuration.