Necromancer

The Necromancer is a hardmode dungeon NPC. They are commonly found in portions of the dungeon with purple triangle banners.

It attacks by firing beams of purple light 6 times at the player which do significant damage. It can be extremely dangerous, as the beams reflect multiple times off walls and travel instantly, making it difficult to reasonably avoid the its attacks. Their beams inflict the slow status.

Whenever it is attacked, it will teleport. This makes the Necromancer frustratingly hard to kill.

However, one easy way to kill them is to play their game with the Shadowbeam Staff they drop. The easiest method by far is using the Piranha Gun or the Scorge of the Corruption, both of which will follow them to wherever they teleport to so long as the trigger is held.

They are immune to the Poisoned and Venom debuffs.