Lunatic Cultist

The Lunatic Cultist is a Hardmode, post-Plantera boss summoned by killing all four Cultists that spawn at the Dungeon's entrance after Golem is defeated. Beating the Lunatic Cultist initiates the Lunar Events.

The boss only has one defined stage, but its attacks become progressively stronger as it loses health. During the fight, the boss will fly around seemingly at random, firing lightning, fireballs, shadowflames and exploding packed ice at the player. It also has the ability to fire five destructible stardust-like projectiles twice in a row. In addition, it will often project illusory duplicates of itself, only one of which can be attacked to deplete the boss's health. Each time the player attempts to attack one of these illusions, the Lunatic Cultist summons a Phantasm Dragon, a Wyvern-like enemy, to attack the player.

It is recommended to avoid defeating the Lunatic Cultist if you are unprepared for the Lunar Event and/or the Moon Lord, as after beating the Cultist the Lunar Event begins immediately, while defeating the event spawns the Moon Lord.

It is highly likely that when you defeat the Lunatic Cultist that you will end up over one of the Celestial Towers or near it when it spawns.

Trivia

 * Its lightning attack seems to be fired from a giant and immobile Magnet Sphere.
 * The packed ice it fires is similar to that of the Ice Queen.
 * It appears visually similar to a plague doctor, a kind of physician who treated the Black Plague in the fourteenth century C.E.
 * It is the smallest boss.

Bugs

 * If you die while fighing the Lunatic Cultist, you may find no drops, and he may not respawn, nor will the altar.
 * Running too far away from the Lunatic Cultist (by means of sheer speed or teleporting) will cause him to despawn. In this case the cultists at the dungeon entrance will not respawn, making it impossible to fight him again