Ophelia

A mysterious woman who tends to the Great Tree Escalus. She has a sad, doll-like face with some marks on her forehead and cheeks, and speaks in a rather polite and mysterious manner. She appears to be ageless as she looks the same as she did fourteen years ago. She eventually explains that Escalus is fading and has implanted its seed inside Juliet, telling the girl the tree's will late in the series. She is a part of the tree, and underneath her robes are wood-like limbs and skin. During the climax, she steals Juliet away and forcibly begins the rites of sacrifice, determined for the Tree's revival with little care for interruptions or alternatives.

In the final battle for Juliet's safety, she mortally wounds Romeo shortly before being vanquished by him. Her name is likely a nod to the heroine of Shakespeare's famous tragedy, Hamlet. [Wikipedia]