Necromancer

The Necromancer is a Hardmode dungeon enemy. It will spawn in the dungeon only after Plantera has been killed.

It attacks by firing beams of purple light 6 times at the player, then teleporting and repeating. These beams are extremely dangerous, as the beams deal significant damage, reflect multiple times off walls and travel instantly, making it difficult to reasonably avoid its attacks. It also inflicts the Slow debuff.

Whenever it is attacked, it will instantly teleport. With this and its attacks, it makes the Necromancer frustratingly hard to kill.

They are immune to the Poisoned and Venom debuffs and only spawn in dungeons with a Brick Wall.

Tips

 * Though the Necromancer's attacks are difficult to avoid, not being in line-of-sight with the Necromancer may help, as its attacks are directed at the player, regardless of obstacles, and as such, the beam may reflect in the complete opposite direction. Using this method to avoid attacks, weapons that fire through walls may be more useful, such as the Nettle Burst.


 * One easy way to kill them is to play their game with the Shadowbeam Staff that they drop.


 * The easiest method by far is using the Piranha Gun or the Scourge of the Corruptor, both of which will follow them to wherever they teleport to so long as the trigger is held. You could also use the Magnet Sphere to shoot lasers hitting them every time they teleport with great accuracy, though in smaller less easily traversable areas, this may not be suggestable.


 * Summoning a Pygmy may be useful as it continually attacks the Necromancer, giving it no opportunity to attack.