I think that adding a necromance would be a good , fun and new class. I think that it should be a class obtained from quest lines such as the rune mage (probably in a cemetary).
The necromancer’s main weapon could a scythe that he could use as melee , he could use his health to attack as well and the health of his minions or his minions or his main weapon could be his minions.
The necromancer’s abilities could be the corruption of weak enemies (lower than his level) without the need to kill them , he could start with some minions or he would have to kill enemies with his weapon or health to then turn them into his minions. He could sacrifice his minions for health or an attack or ability or just for a buff , he could also take controll of one of his minions , that minion would get a buff and abilities that he can use to fight but leaving himself vulnerable. The stronger the enemy he kills and then corrupts , the stronger the minion that comes out of it will be or maybe multiple minions could come out of 1 strong enemy. He could also sacrifice other minions to make stronger minions by uniting them. Smoke could come out of the enemies he kills making the player know that he can get minions out of them or that he can get health , buffs or abilities, attacks and more out of them. The necromancer could also be able to convert players he killed in the wilds into his minions. The life force he takes from enemies he could also give to his teammates or his minions to heal them , buff them up or in the case of his minions enhance them.
The necromancer should probably not be able to get minions from enemies that he didnt kill or atleast that his party members didnt kill. The necromancer should not be able to convert some enemies for example bosses or special quest enemies.
If a limit is put on the number minions a necromancer it is understandable , imagine a person running around with 20 to 30 minions , it would be op but it would also cause lag. In the skill tree one of the skills could probably increase the limit .
If a limit is not placed a few ways to balance the necromancer is by making his minions take the same damage and debuffs as yourself when you are attacked making you the target but if this is the case any buff placed on you and healing done to you should also go to your minions , another way is to make the necromancer weaker and give him debuffs for evey minion he has again making him the target and another way could be by making his minions rot away and die after a certain amount of time. All of these debuffs could add skills to the skill tree to decrease them , like increase your minions rot time so they stay longer , he should also be able to give his minions his health or life force to make them last longer.
He should also probably have a life force bar for all of it that he robs from enemies ,any damage he takes should turn life force into health and once he runs out of life force he should be able to use his health for abilities but that bar should also have a limit making it so that if the necromancer doesnt spend it he gets no more or he should not have the two bars and just use his health bar for all of it.
He could be able to customize his minions gather parts and abilities from different enemies and be able to summon the minion he made by spending a life force depending on how strong it is or by just placing it down and spending a bit of life force to bring it to life or just leave different tiers to the minions of how strong a monster they came from or how much life force you give them.
His abilities could be orbs or rays of life force or if he has a scythe he can slash his scythe to unleash a ranged attack ( a line of life force ) , he could also steal the life of enemies or curse them with debuffs , like making them rot and a lot more.
He could activate his spells or abilities by drawing like rune mage or through books like paladin on by hand signs he can do.
These are just examples of how a class like this vould work or be
This is a class I would to see in orbus
Theres also another way to get a character that summons things in “the summoner” its the same premise but that the summer is a little bit more alive but there still a bit different and have different abilities I could make one on the summoner as well.