I have no enemy on earth
This is, indeed, the case, and this fact deeply complicates the novel. The Creature incriminates Justine not because he knows, as with William, of a connection to the Frankenstein household, but because she is a person whose ordinary sympathies, he presumes, would be blocked in his presence. Without thinking, he too victimizes Justine, and he does it on the grounds, since sympathy is more readily expected of women, of her gender. For his explanation, see II:8:35.