Celestial Pillars

The Celestial Towers are four Bosses that appear during the Lunar Events when the Lunatic Cultist is defeated. There is the Vortex Pillar, the Stardust Pillar, the Nebula Pillar and the Solar Pillar. You have to defeat 100 enemies (150 in Expert Mode) before you can destroy them. The craftable gear from each correspond to the 4 main classes in the game, Vortex for ranged, Stardust for summoner, Nebula for magic, and Solar for melee.

If you exit the game without destroying a Pillar, all progress made will be reset.

Defeating each triggers the following status messages:
 * First Tower destroyed: "Your mind goes numb..."
 * Second Tower destroyed: "You are overwhelmed with pain..."
 * Third Tower destroyed: "Otherworldly voices linger around you..."
 * Fourth Tower destroyed: "Impending doom approaches..."

After defeating all four Celestial Towers, the Moon Lord will spawn.

Vortex Pillar
The Vortex Pillar is one of the four Celestial Towers. It appears during the Lunar Events when the Lunatic Cultist is defeated.. It is found in the green moon area. After defeating the tower, it drops around 30-40 Vortex Fragments on average. It is the ranger-themed Tower.

During the battle the pillar will start with a large force field around it, which can be taken down by slaying 100 minions (150 in Expert Mode). Once the field is down, the pillar will become vulnerable, but minions will continue to spawn. The boss itself is fairly easy, having only 20000 HP and you take no damage when touching the pillar melee. While the boss may not be a threat, the minions it spawns deal high amounts of damage and can easily swarm the player if not taken care of.

Gravity around it does not work as in other places, instead pushing player up in the air to some height in similar way as water does with slimes.

 Summons :

Stardust Pillar
The Stardust Pillar is one of the four Celestial Towers. It appears during the Lunar Events when the Lunatic Cultist is defeated. It is found in the bluish/whitish moon area. After defeating the tower, it drops around 30-40 Stardust Fragments on average. It is the summoner-themed tower, and remains true to the theme with a unique ability to summon more of its minions with a special summoning animation.

During the battle the pillar will start with a large force field around it, which can be taken down by slaying 100 minions (150 in Expert Mode). Once the field is down, the pillar will become vulnerable, but minions will continue to spawn. The boss itself is fairly easy, having only 20000 HP and you take no damage when touching the pillar melee. While the boss may not be a threat, the minions it spawns deal high amounts of damage and can easily swarm the player if not taken care of.

Summons :

Nebula Pillar
The Nebula Pillar is one of the four Celestial Towers that appear during the Lunar Events when the Lunatic Cultist is defeated. It can be found in one of four predetermined spots during the Lunar Events. It drops around 30-40 Nebula Fragments on average. It is the magic-themed Tower.

During the battle the pillar will start with a large force field around it, which can be taken down by slaying 100 minions (150 in Expert Mode). Once the field is down, the pillar will become vulnerable, but minions will continue to spawn. The boss itself is fairly easy, having only 20000 HP and you take no damage when touching the pillar melee. While the boss may not be a threat, the minions it spawns deal high amounts of damage and can easily swarm the player if not taken care of. While near this boss, the player's screen will take on a dull purple shade, tinting all blocks, players, monsters, and the sky purple.

Summons :

Solar Pillar
The Solar Pillar is one of the four Celestial Towers that appear during the Lunar Events when the Lunatic Cultist is defeated. It is found in the orange/red moon area. Many of the enemies that spawn near it are melee-themed. After defeating the pillar, it drops around 30-49 Solar Fragments on average. As it has melee-themed enemies it drops fragments used to create the endgame melee armor and weapons.

During the battle the pillar will start with a large force field around it, which can be taken down by slaying 100 minions (150 in Expert Mode). Once the field is down, the pillar will become vulnerable, but minions will continue to spawn. The boss itself is fairly easy, having only 20000 HP and you take no damage when touching the pillar melee. However it will occassionally shoot out meteorites that deal around 90 damage per hit. While the boss may not be a threat, the minions it spawns deal high amounts of damage and can easily swarm the player if not taken care of.

Summons :

Tips
For all Celestial Towers :
 * A quick and effective way to kill all of the pillars is to use the North Pole directly and vertically above a pillar. Even if a player does not have any melee modifiers, if all of the snowflakes can make contact, the pillar should fall in less than 20 seconds.
 * Another strategy is to use the Nimbus Rod as you can leave the place and let it deal damage, placing 2 clouds, you just need to resummon it once, or even none at all. If you leave a nimbus cloud above the tower and teleport away, it will still do damage until either the tower dies or the cloud runs out. Can be combined with regenerative Spectre armor for long distance healing, as the healing orbs have a very large range, extending well from the tower area.
 * Some other weapons might be more effective, but they are not obtainable until first pillar is destroyed. Therefore, if you decide to start with the Vortex Pillar, using the Phantasm will be incredibly faster for the next ones.
 * Some Pillars and their enemies seem to be weak to their own weapons. For example, the Nebula Pillar is weak to the Nebula Blaze and Nebula Arcanum.
 * The longer the time taken to defeat a pillar, it will go deeper in the ground (very slowly)


 * Repetitively throwing Vampire Knives will keep you healed most of the time, and if you get to less than 150 hp, use a Greater Healing Potion or higher. This will slowly take out the enemies and the pillar itself. Switching to another weapon is a bad idea, unless you have full Spectre Armor with a hood, though following this strategy, you should have Beetle Armor.

For Vortex Pillar :

For 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.
 * Arguably, the Stardust Pillar is the easiest of the lot; its enemies are predictable and slow in their motions, and with focus, even the most menacing of the lot, the Flow Invader, can be easily countered.

For Nebula Pillar :

For Solar Pillar :
 * While fighting the Solar Pillar enemies, it is highly recommended to stay grounded. Airborne players are easy prey for the Crawltipede minions, who do an excessive amount of damage.
 * If you have already problems killing the enemies to get the shield down, a good and easy way is to dig a tunnel under the Pillar and use weapons that go through walls like the Death Scythe or the Nettle Burst. It will help a lot using the spore sac (Plantera Expert Item) and a random minion. You can also kill the Pillar using your wall piercing weapon. If it's stuck on a hill, you can build a non-platform bridge to it without being assaulted by Crawltipedes.

Trivia

 * The Nebula Pillar is the only pillar to not have an attack that damages directly, as the Solar Pillar attacks with solar flares, the Vortex Pillar summons portals that either shoot lightning or spawn Alien Hornets, and the Stardust Pillar attacks by summoning white portals that either spawn Star Cells or Milkyway Weavers.

History
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