Using death and blood or even just bones in spells, animating skeletons or dead bodies -- yeah, that's a necromancer.
It's the ones who deal with ghosts that have issues. What does it mean to summon a soul? From the afterlife? Can they only seize the soul in the liminal time after death and before escape to the afterlife? Is that long? Does a funeral end it? Is it a year and a day? Do they actually have to seize the soul while the person is dying? Can some souls escape regardless?
If they can summon them back, what can the ghosts reveal? And will they? How free are they?
Can they come back without the necromancer's power and just be vulnerable to it after? Or is the return of a vengeful ghost a great peril to a necromancer who just wanted the death to power to the spells?