Necromancer are offensive spellcasters specializing into dark magic. They can use all weapons and wear robes.
Necromancers have a broad palette of curses, especially Curse Discord to make one enemy attack another, Curse Fear to make them flee, Curse Poison for damage over time, and the powerful Anchor spell which paralyzes the victim, as well as Forget to make victims unaware of previous attacks, plus quite a number of Debuffs. Against other spellcasters, they have the special spell Silence.
As nukers, they get the spells Vampiric Claw, which does much damage and heals the caster from it, but has a high mana cost, and Death Spike, which costs very little mana, but consumes a cursed bone which one can't buy in the shop and is only dropped sometimes by certain undead opponents, and later Curse Death Link, which has ok damage and cost, but most importantly gets stronger the lower the hp of the caster drops. They can also use Corpse Burst to let fallen victims explode and damage bystanders. Their other mass spells are Mass Slow and Poisonous Cloud.
They can also do some summoning (Summon Corrupted Man for 90% xp loss, Summon Reanimated Man for 30% xp loss), but they lack all the spells to support their summons any further, like healing and buffing, so they will have to rely on their lowlevel spells alone to strengthen the summon, and directly help their summon with their debuff magic. They can however use Transfer Pain to move damage made on them into their summon.