I think that, overall it would be more like Cass Cain at a KKK Rally, since Ciel has generic anime super stats and is a powerful mage (who specializes in lightning, IIRC) in her own right, though I think that only the (excellent) manga really does anything with that aspect of her skillset. Especially if this is before she loses her immortality, since I doubt that Avada Kedavera will really do anything to her considering that her important is based on her soultechnically being in two places at once.
Huh. It occurs to me that Ciel's soul is technically fixated on three fifths of the other members of the main Shiki Tohno love hexagon. No wonder Arcueid thought that inserting herself into Ciel's love route would work, considering that Ciel is the only natural reincarnation of the man who fell in love at first sight with Arcueid.