The Necromancer is a class that mainly focuses on summoned minions. The skill tree covers a broad range of minion stat bonuses, but also bonuses specific to zombies, skeletons, and spectres. While most of the tree is minion-centric, it also offers bonuses not directly related to minions, such as Mistress of Sacrifice which grants offering bonuses to themselves and damage from using corpse, and Commander of Darkness which benefits aura-based builds.
Necromancer is a powerful option for BD that mainly deal damage to enemies with Minions. It is a good choice in the three Witch Ascendancy for a wide range of Spectre in PoE. Player can build many ways to play by selecting different kinds of Spectre.
Therefore, the Necromancer should pay attention to the choice of fit Minions and Spectre. Players can prioritize stay safe and leave the rest to us. And we will offer relative Necromancer BD to provide a reference for you. For example, Witch Summon Complete Guide.