I could be proven wrong, but I really don't think Comfrey is the bbeg. I think she's something much more mundane than that:
she's the absentee parent who insists she's the greatest who ever lived because you always have the most fun when she's around, until you grow up and realize how infrequent and shallow those visits were.
she's the mentor who believes in you and makes you better, but pushes you too hard and too fast because she sees you as an extension of herself instead of your own person, and she abandons you when you fall behind.
she's the lover who charms you and sweeps you off your feet, and constantly breaks your heart, and acts like you're the bad guy for finally walking away.
she's the friend who wants to share all your deepest secrets and dreams, then throws your insecurities in your face at the first sign of conflict and cuts you off completely when you dare to stand up for yourself.
she's the person closest to you that praises and relies on your loyalty time and time again, yet always lets you down when the roles are reversed.
she's the hero of her own story, and it sucks because she's not entirely wrong: she makes big waves and changes the world and excels at everything she sets her mind to—except for consequences, and apologizing, and making amends, and admitting when she's wrong.
she's flawed and selfish and committed to her own ambition at the cost of her relationships.
she's not evil, but it would be easier if she was.