Celestial Pillars

The Celestial Pillars (also known as the Lunar Pillars, Lunar Towers, and Celestial Towers) are four mini-bosses that appear during the Lunar Events, when the Lunatic Cultist has been defeated. They appear at four locations equally spaced across the map (see Pillar Spawning Mechanics), and are completely stationary, apart from slowly bobbing up and down in place. Each pillar takes control of the map in a large area around them, around 500 tiles in each direction. The affected area will show that pillar's background and spawn the pillar's specific enemies in large numbers.

The four Celestial Pillars are the Vortex Pillar, the Stardust Pillar, the Nebula Pillar and the Solar Pillar. The craftable gear from the pillars correspond to the four main classes in the game; Vortex for ranged, Stardust for summoner, Nebula for magic, and Solar for melee.

Initially, the Celestial Pillars have a large force field around them, which prevents them from taking any damage. In order to remove the force field, the player needs to defeat 100 / enemies that correspond to that particular pillar. After doing that, the force field will lower and the pillar can be damaged. Enemies will continue to spawn until the pillar is defeated. If the player exits the world without destroying a pillar, all damage done to it will be reset, and the kill count needed to remove the shield will also reset. However, player deaths will not reset them. When destroyed, the Celestial Pillars each drop between 12–60 / Lunar Fragments of their type.

The Pillars themselves are fairly easy to defeat, having only HP each and having weak attacks (none in the case of the Nebula Pillar). The direct threat comes from the minions they spawn; they can deal high amounts of damage, can inflict debuffs, and easily swarm the player if not dealt with quickly.

There is no set order in which the Celestial Pillars must be defeated. However, players usually go for whichever pillar is closest or is weakest to their class. The following status messages will appear from whichever pillars are taken down first, second, third, and fourth:


 * First pillar defeated: ""
 * Second pillar defeated: ""
 * Third pillar defeated: ""
 * Fourth pillar defeated: ""

After defeating all four Celestial Pillars, the screen will start to vibrate, and the music volume will lower before eventually going completely silent. One minute after the Pillars' defeat, the Moon Lord will spawn.

Vortex Pillar


The Vortex Pillar is the ranger-themed Pillar, with fast, mobile minions capable of long-ranged projectile attacks. When nearby, the world is tinted teal, and the background will display a teal planet with lightning. It drops Vortex Fragments when defeated.

It will occasionally open a portal above the player that spawns two Alien Hornets.


 * Storm Divers shoot a small volley of projectiles that deal very high damage.
 * Alien Queens can fire stingers that cause the Distorted debuff, which causes the player to be unable to fly upwards or fall downwards for a few seconds, forcing them to only be able to move horizontally.
 * The Alien Queen spawns 3 Alien Larvae when killed, which will grow to Alien Hornets and into more Alien Queens if they are left for too long.
 * Vortexians are fighters that, on death, summon a portal which shoots a lightning bolt that deals relatively low damage.

Stardust Pillar


The Stardust Pillar is the summoner-themed Pillar, with large swarms of enemies that spawn smaller, weaker entities to attack. When nearby, the world is tinted blue, and the background will display a blue planet and a sparkling effect. It drops Stardust Fragments when defeated.

The Stardust Pillar is able to spawn enemies above the pillar on screen. The Stardust Pillar will spawn multiple energy orbs above it, and will link together with lines and then disappear, spawning in a random enemy.


 * The Milkyway Weaver is similar to the Crawltipede by flying and attacking players in midair, but it is smaller and can only be damaged on the head.
 * The Star Cell enemy, if killed, will split into smaller sized versions that grow into full sized versions after a few seconds, which can cause enemies to fill the screen.
 * The Flow Invader will summon smaller creatures around it, which will shoot themselves like projectiles at the player after there are three around the Flow Invader. The smaller creatures around it will become projectiles and shoot towards the player after the Flow Invader is killed, and can deal massive damage.
 * The Twinkle Popper, along with dealing contact damage, releases a small enemy called a Twinkle that chase players and explode to deal heavy damage.
 * The Stargazer runs after players and conjures powerful lasers to damage them.

Nebula Pillar


The Nebula Pillar is the mage-themed Pillar, with minions capable of flight, teleportation, and other unusual attacks and abilities. When nearby, the world is tinted pink, and the background will display a pinkish-purple planet with beams of energy pulling debris into the sky. It drops Nebula Fragments when defeated.

The Nebula Pillar is the only pillar that does not have any attack of its own. In addition, its enemies have a pulsing aura effect to make them easier to see.


 * The Nebula Floater shoots lasers that move very fast and deal large amounts of damage. It will teleport around the player when hit, making it more difficult to dodge its projectiles.
 * The Brain Suckler can attach itself to the player, inflicting the Obstructed debuff and dealing damage.
 * The Evolution Beast shoots projectiles that chase the player and deal high damage multiple times.
 * The Predictor shoots 4 fast-moving, very high-damage projectiles at once.

Solar Pillar


The Solar Pillar is the melee-themed Pillar, with minions that bear strong defensive abilities and deal heavy contact damage. When nearby, the world is tinted orange, and the background will display a massive orange planet with a shower of falling meteors. It drops Solar Fragments when defeated.

The Solar Pillar will continuously spew fireballs that deal high contact damage.

The Solar Pillar is widely considered to be the most difficult of the four, due to the crawltipede forcing the player to stay grounded, leaving them vulnerable to the variety of other ground enemies that the pillar spawns.


 * The Crawltipede is a long, fast-moving worm-like enemy that can only be damaged on its tail. It is passive while the player has blocks under their feet, and only starts attacking once the player takes flight. While it has high health, damage against it is multiplied by 10.
 * The Sroller can curl into a ball and roll at the player, potentially dealing a large amount of damage on contact.
 * The Corite is a flying enemy that can shroud itself in fire and charge towards the player at high speeds, traveling through blocks.
 * The Selenian is a ground-based enemy that wields two flaming swords. It can curl up and fly towards the player at high speed. When it does so, it will reflect certain player-fired projectiles.

All Pillars

 * A player can tell if they have reached the kill count or not by seeing if, after killing an enemy, a colored line travels from the corpse to the Pillar. If the line doesn't appear, the kill count has been reached. As well, the shield surrounding the Celestial Pillars becomes more transparent as it becomes closer to breaking. If the player is using the lighting type "Color", they can look for the shockwave that the pillar sends in all directions before breaking.
 * Before starting the Lunar Events, it's worthwhile to lay a teleporter line across the map, with enough stations that the player can at least choose which pillar to approach first.
 * Some enemies can travel or attack through blocks.
 * For this reason, if a player has an effective weapon that can deal damage through walls (such as the Solar Eruption), they can for the most part build a shelter under the surface and attack these incoming enemies. This strategy is the most difficult for the Nebula Pillar due to the Evolution Beast's spit-like projectiles and the Brain Suckler's debuffs.
 * The weapons gained from defeating the first pillar(s) can be very helpful in defeating the others. The Solar Pillar yields the Solar Eruption and Daybreak, the Vortex Pillar gives the Phantasm and Vortex Beater, the Nebula Pillar provides the Nebula Arcanum and Nebula Blaze, and the Stardust Pillar enables the Stardust Dragon Staff and Stardust Cell Staff.
 * It may be best simply to target the pillar matching the player's preferred class, thus gaining at least one powerful weapon of it.
 * Players can use the GPS to know the height of one Pillar, build/expand a nearby building to provide a firing platform at this depth, then pelt the Pillars with a Rocket Launcher, optionally backed by a Sniper Rifle. The time the rocket takes to reach a pillar can be long: in a large map, a Rocket takes ~1 min to travel from the center of the map to the farthest Pillar.
 * If the player or players have acquired the Vampire Knives once a pillar's shield is destroyed the player can regenerate health extremely fast by firing the knives at point blank range at the pillar.
 * A strategy for taking out the Pillars is to stand near the edge of a pillar spawning area and to retreat and recover when at low health until its shield is down.

Vortex Pillar

 * If the player sees a swirling portal in midair, they should keep their distance and move quickly. The portal will either shoot a lightning bolt similar to the Lunatic Cultist's attack or spawn an Alien Hornet.
 * When the portal shoots a lightning bolt, there will be a blue swirling marker pointing towards the direction the lightning bolt will strike at, but they will only shoot downwards.
 * The Vortex Pillar will always spawn Alien Hornets on back-walls with a direct line towards the player if there are any on its screen. If not, it can spawn Alien Hornets anywhere within an approximate 300 block radius of the Pillar.
 * Because most of the enemies try to stay at the same elevation as the player, staying on the ground removes much of the mobility that Alien Hornets and Storm Divers have.
 * This is the only pillar where enemies or projectiles can't travel through blocks, and thus, taking cover is very effective. However, it is somewhat slow as many enemies keep their distance.
 * Avoid getting swarmed by Alien Queens, as they easily grow from Alien Larvae and Alien Hornets and the Distorted debuff greatly decreases the player's flighting and agility.

Stardust Pillar

 * Using splash-damage weapons on Star Cells is perhaps the easiest way to kill them, as it will destroy all of the split cells as well as the initial cell.
 * A quick and easy way to break the shields is to lead a Star Cell away from the Pillar, pop it into its smaller orbs, then let those orbs grow into full star cells. This creates an infinite loop, and the new ones will also count towards the counter.
 * On death, the Flow Invader will hurl up to three projectiles directly at the player. Be ready to dodge when the player kills this creature.
 * Stargazer lasers deal very high damage, but they have difficulty targeting the player without direct line of sight. Weapons that ignore terrain or can go around it will be very effective, such as Yoyos, Minions and Chlorophyte Bullets.

Nebula Pillar

 * When fighting, take caution to avoid getting hit by a Brain Suckler. They cause the Obstructed debuff, which is similar to Darkness but with a darker shade. It will persist until the player kills the Brain Suckler stuck to them, and for a moment thereafter.
 * Be very wary of Nebula Floaters. They do high damage with high accuracy, and their tendency to teleport, especially when harmed, can make them unpredictable.
 * They can also teleport directly in front of the player and fire at point blank: if the player wouldn't survive another shot and can't heal up, it may be best to retreat. Be careful when flying in a straight line, as the Floater will deal potentially fatal contact damage if it teleports in front of you.
 * Kill Evolution Beasts quickly, because once they get in range they will fire a slow but highly damaging ball of energy that tracks the player, passes through walls, can deal continuous damage, and only expires after a few seconds. These will force the player to move around into other hazards.
 * Keep an eye out for Predictors because they will stay at distance, not attempting to get close to the player, and shoot several Nebula Piercers in a similar fashion to how Storm Divers fire their shotguns.

Solar Pillar

 * While fighting the Solar Pillar enemies, it is highly recommended to stay grounded. Airborne players are easy prey for the Crawltipede minions, which do an excessive amount of damage, but only attack them.
 * If the player has a skybridge set up in their world, standing on it will allow them to shoot down at enemies on the ground and even the pillar without being targeted by the Crawltipedes. Keep in mind Srollers will still be able to jump up to the platform and roll towards the player.
 * It is highly suggested not to use bullets, arrows, or most projectiles that aren't Rockets, at least not on Selenians, as they can reflect non-Rocket projectiles. These projectiles will deal the same damage to the player that they would have dealt to the Selenian.
 * If the player has a Neptune's Shell, a combined accessory with its effect, or Gills Potions, then standing in a large pool of water under or near the pillar will allow them to move around off the ground, without being targeted by Crawltipedes. In addition, this will also cause most enemies, with the exception of Corites, to move slower, and make it easier to target them.
 * If available, the Scutlix Mount improves forward firepower and ground maneuverability considerably, making the fight much easier.
 * Although, the Selenians can reflect the lasers.
 * When fighting the Solar Pillar, try building a small building with doors, platforms, and make it two floors tall, right on the edge of where the Pillar starts spawning enemies, to help block off some enemies from swarming the player, and to force them into a small and easy to defend area. Only the Corites will fly through walls.
 * Oddly, enemies that the Solar Pillar spawns are not immune to the On Fire! debuff.
 * Weapons such as the Possessed Hatchet or the Stardust Dragon Staff will only target the tail of Crawltipedes, and this can kill them quickly and easily, making the fight much easier.
 * With a ranged weapon, you can lock the Corites in place by shooting them while they are spinning.

Pillar Spawning Mechanics
When it is time for the four pillars to spawn, the game follows these steps: (The coordinates are in tiles)
 * 1) Randomly arrange the order of the 4 pillars.
 * 2) Multiply the width of the world by 0.2, 0.4, 0.6, and 0.8 to find rough spawn locations for the pillars, equally spaced from each other and the world's edges. (For example, a large world is 8400 tiles in width, so the 4 pillars will be spawned at somewhere near x=1680, x=3360, x=5040 and x=6720.)
 * 3) For each pillar:
 * 4) Pick a random x1 coordinate in the range [x0 - 100, x0 + 100], where x0 represents the x coordinate of the location the Pillar was assigned to.
 * 5) Try to find out a possible y1 to spawn the pillar at (x1, y1). The y1 is processed from the 0′ surface point to somewhere 100 tiles below the top of the world, from low to high. This place is a valid spawning space for a pillar if:
 * 6) * There are no solid blocks (does not include platforms and other similar tiles) in the rectangle of x coordinate [x1 - 10, x1 + 10], y coordinate [y1 - 20, y1 + 15] (the smaller the y is, the higher height the spot lies).
 * 7) * The pillar will be outside the player's sight, checking whether tiles (x1 - 10, y1), (x1 + 10, y1), (x1 - 10, y1 - 20), (x1 + 10, y1 - 20) are all outside a rectangle centered at the player with a width of 1920*1.2 pixels and a height of 1080*1.2 pixels.
 * 8) If a y1 works, then the pillar spawns at (x1, y1).
 * 9) If none of the valid y1 works, go back to the first step.
 * 10) If all steps have been run 15 times and failed, give up and just spawn at a settled point: (x0, y0 - 40), in which case the pillar will always spawn at 80′ surface at a fixed x coordinate.

Pillar Relative Location
Using the above spawning mechanics, the location of each pillar can easily be computed relative to the world's default spawn point (i.e. the center of the map).

Assuming S is the world size (in feet) and PX is the location factor (0.2, 0.4, 0.6, 0.8) for pillar X, then the relative location can be computed as RX = (S * PX) - (S / 2).

Trivia

 * Correspondences:
 * As noted above, both the craftable gear and the enemies from the pillars correspond to the four main classes in the game: Solar – melee, Vortex – ranged, Nebula – magic, Stardust – summoner.
 * When in a pillar's area, the entire area nearby will turn the pillar's color: Solar – orange, Vortex – teal, Nebula – purple, Stardust – blue). This effect will only occur if the lighting mode is on "Color" or "White".
 * The four pillars could also be based on the lifespan of a star: Solar – a living star, Vortex – a collapsing star as it dies, Stardust – the remains of a star's corpse, and Nebula – the birth of a new star.
 * Occasionally, the background scenery of the biome the pillar is in will overlap with the background scenery that appears when near the pillar (see image on the right).
 * All of the Celestial Pillars have a humanoid enemy. Solar Pillar: Selenian and Drakanian; Vortex Pillar: Vortexian and Storm Diver; Stardust Pillar: Stargazer; and Nebula Pillar: Predictor.
 * The Nebula Pillar is the only pillar to not have a directly damaging attack; the Solar Pillar attacks with fireballs, the Vortex Pillar summons portals that spawn Alien Hornets, and the Stardust Pillar summons portals that spawn any enemy.
 * If the Lighting mode is set to "Color" or "White", the shield will have a distortion effect. When the shield is down, it sends a shockwave in all directions. These effects do not occur in the "Retro" or "Trippy" modes.
 * Reversing gravity with a Gravitation Potion or Gravity Globe has a strange effect on a pillar's shield. Instead of being stationary around the pillar like it normally would, its vertical position changes according to its relation to the player. This is only cosmetic, as the pillar cannot be attacked when the shield appears to be removed.
 * The projectile spawned upon a celestial enemy's death (until the pillar's shield falls) is called "Released Energy" and has the projectile ID 629. A player can spawn this projectile using mods. If one is spawned while there are no pillars, it will target the Old Man by the Dungeon. If the Old Man is not present, the Released Energy will despawn immediately.
 * Quitting and re-entering the game will put the pillars at the top of their bobbing motion while maintaining their position, causing them to sink slightly.
 * All of the Celestial Pillars have 2 health bars, the shield (blue) and the pillar itself (red). This makes the Celestial Pillars the only boss in the game to have 2 separate health bars.

History
Tours Célestes 天界柱