I like to think the necromancer as a corrupted mage, so I would like his weapons to reflect the dark versions of the mage weapons: bone wands, staves with skulls on top that summon a dark scythe for close combat, dark and demonic grimoires, and instead of a magic orb a skull imbued with dark magic on which the necromancers carves ominous runes with a dagger to cast spells.