When I say necromancy, I do not just mean talking to the dead. The term is vague but even talking to ghosts is a form of it although in Lavenderism it would be called ghost worship and not considered too close to actual death energy based necromancy. The necromancy I’m talking about is not just dealing with a virgin ghost in the bathroom, I mean summoning a god of death (Or other energies that work for the same purpose) and directing death energy through you to accomplish tasks. Some practices are just raising the soul of a dead person to speak with them, but the greatest risk with those are imposter spirits. If you begin working with actual death energy necromancy, you can physically rot, you can have people around you die or die yourself, and even those who survive end up with health issues they need to manage.
A pro is that you experience a new dimension of existence, because it is very rare for most people to be touched by death energy while still alive. The con of this is that death essence (Energy from necromantic death workings) can cling to you and cause health problems or death to you or those close to you. This is especially true if you are using magic to make people or things die, since you are channeling that energy through yourself. You would be much better off to work with life energy and healing since it would affect you similarly and in a positive way.
Another thing that can either be a pro or a con for necromancy is that it is extremely dark. Some will be turned off, and others would like it. Some who like dark things might even try it if it wasn’t for health concerns. There are also some illegal aspects that include grave robbing or using the dirt from the grave of a dead person so they may help you out as a ghost in exchange for compensation. This is not to be done lightly and only the ghosts of magicians. You don’t need to graverob ancestors either because you are already connected to them, while this random magician is just kind of someone you take the graveyard dirt from, knock on their door, and hope they feel inclined to help you.
So while there are benefits to working with death energy in different ways, it is extremely difficult, dangerous, and it is not something that should be picked up casually at all. Those who naturally resonate with death energy usually also resonate with life energy, which also has benefits such as assisting in the care of plants, pets, and children as well as improving your own health and fertility over time. Life energy is also useful for anything related to nature such as crops, livestock or trees.