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 repeatedly summons the Phantasm Dragon, a Wyvern-like enemy, to attack the player. In addition, it will often project duplicates of itself, only one of which can be attacked to deplete the boss's health. May be a refrence to plague knight from shovel knight
 * Refrence