I’m a Metaphysics Master. What’s Wrong with Scattering Your Ashes?

Mysticism, but Nothing Too Childish

Metaphysics: A Powerful, Knowledgeable Heroine Who’s Good at Everything

Romance for the heroine is optional. I just want her to be very familiar with the Underworld and have good relationships there. The Underworld’s residents can be afraid to mess with her, or she can be their favorite. She should know lots of powerful people, whether in Heaven, the Underworld, or the human world.

Please Recommend Ghost-Hunting and Metaphysics Novels. I've Been into This Genre Lately

Thanks! Completed or ongoing stories are both fine.