Quote 10
I am alone in the castle with those awful women. Faugh! Mina is a woman, and there is nought in common. They are devils of the Pit! (4.67)
Here, Harker contrasts the three Brides of Dracula with Mina. We're invited to think of them as the complete opposite of Mina.
Quote 11
At least God's mercy is better than that of these monsters, and the precipice is steep and high. At its foot a man may sleep—as a man. (4.70)
It's interesting that Jonathan adds "—as a man" at the end, because at this point, he has no way of knowing that the vampires' kiss could turn him into a vampire. All he knows is that "those awful women" want to suck his blood and that Dracula, too, is some kind of monster. Maybe Harker thinks that being victimized by the three "weird sisters" would somehow make him less of a man.
Quote 12
But my very feelings changed to repulsion and terror when I saw the whole man slowly emerge from the window, and begin to crawl down the castle wall over that dreadful abyss, face down, with his cloak spreading out around him like great wings. (3.22)
This is one of the first hints Jonathan has that the Count isn't quite… human.