What is significant of the last sentence in chapter 16?

The sentence goes, "My companion must be of the same species and have the same defects. This being you must create."

It is important to note that the creature's murder of William and mistreatment of Justine are the result of his longing for human connection. Upon seeing William, he wishes to keep the boy as his companion; the sight of Justine fills him with love and desire. He can have neither of them; neither is willing to overlook his external ugliness. It is therefore only fitting that he should end his tale by asking Frankenstein to make him a female companion, since all of his crimes arise out of his crushing loneliness. Shelley seems to suggest that isolation so total would drive anyone mad; the creature thus cannot be held responsible for his actions.