The show never said what Brenda is but after the revenant vanquishing spell didn't work on Brenda, Mel said "figure out what the hell this is" so they could vanquish her. Then Harry opened the book to another page to explain that mortals can sometimes conjure ghosts and that the ghost can only be vanquished by healing the conjurer's pain. I feel like a "conjuring" could be the best name for Brenda's type, especially since Harry called out the movie earlier in the episode.
You changed Charity's powers back to apportation because you said the gun reappeared in her hand but it never did. I watched that scene over and over again and the gun never reappeared. She only reached down to grab the paint can to hold the Harbinger but she never had the gun herself. She could have still teleported the gun away somewhere but it seems more likely to me that she disintegrated it due to the effects on the gun.