Guide:The Primordials strategies

The Primordials is a post-Moon Lord boss, serving as the final challenge available in the Thorium Mod, summoned by using a Doom Sayer's Coin anytime at night. The boss consists of three primordial spirits: Aquaius, The Endless Tide; Omnicide, The Life Defiler; and Slag Fury, The First Flame. Each one of these spirits possess their own attack patterns and health. In addition, in Expert Mode, an additional phase serves as the final challenge before stopping The Primordials. As such, players should be prepared to the absolute best they can be before they can emerge victorious as Reality Bearers. The following are some hints, tips, and strategies to help defeat it.

Armor
You should have the strongest armors available for each class: Solar Flare armor for Melee, Vortex armor for Ranged, Nebula armor for Magic, Stardust armor for Summoner, White Dwarf armor for Throwing, Celestial armor for Healer, and Shooting Star armor for Bard. While it is generally recommended to focus on a single damage type to maximize your damage output against The Primordials, the Terrarium armor set provides the best general benefits if you do wish to use multiple damage types for the battle.

Accessories
As with all other Hardmode bosses, a pair of Wings are essential for movement. At this point, the best possible wings you can have are Solar or Stardust Wings, though the other wings crafted using the other Lunar Fragments, as well as Terrarium Wings, can also work. Terrarium Particle Sprinters are the upgrade to Firestorm Boots, and further enhance the player's movement speed and flight time. The dash provided from Master Ninja Gear is useful if you do not want to constantly consume Kinetic Potions, and the accessory comes with the added chance of dodging enemy attacks, which may help negate any dangerous attacks during the encounter.

A large number of projectiles are thrown out during the fight, especially in Expert Mode. As such, accessories that provide immunity to knockback are highly valuable. The best choice for this fight is the Terrarium Defender as aside from preventing the player from being knocked about, it also prolongs the player's invincibility time after taking damage, and provides a wide variety of debuff immunities; the relevant ones for this fight are Frozen and Poisoned (from Tainted Hearts). The Philosopher's Stone or the Charm of Myths shorten the cooldown for healing potions. There are more effective accessories for this battle, but it can be quickly swapped into the player's equipped accessories just to heal, then swap it back and continue fighting. Accessories that can provide extra damage reduction, such as the Worm Scarf, Blast Shield, or Frozen Turtle Shell are especially helpful for increasing your survivability.

Accessories that provide offensive benefits should be used. While these generally differ based on damage type, some universal items include the Celestial Stone and Celestial Shell, the Avenger and Destroyer Emblems, and the Mask of the Crystal Eye. In addition, each classes' respective Emblem are always an option for its solid 15% damage increase.

If you are playing as a Warrior, the Yoyo Bag significantly increases the damage Yoyos inflict, making it a must if you plan on using one. Besides this, the Mechanical Glove is also an option. Do note that the Mechanical Glove is preferred over its upgrade, the Fire Gauntlet, for this battle as The Primordials are immune to On Fire!, making the higher stat increases from the Mechanical Glove more useful.

If you are playing as a Ranger, the Magic Quiver or Sniper Scope should be used if you are using either Bows or Guns respectively for the benefits they provide for their respective weapon type.

If you are playing as a Mage, having an accessory that helps recover mana more quickly is recommended, especially considering some of the high mana costs of endgame magic weapons. The two main choices for this would be the Mana Flower and the Celestial Cuffs. Considering the large amounts of damage the primordial spirits deal, the Mana Flower may be preferred over the Celestial Cuffs for a more consistent mana recovery, but if you will be collecting Life Boosters, then this can be mitigated to an extent.

If you are playing as a Summoner, minions will retain any damage boosts, even after unequipping them, so before the battle, it's best to strap on as much damaging-boosting accessories as possible, before exchanging them with whatever accessory you wish to use against The Primordials. Examples of this include the Summoner Emblem, the Papyrus Scarab, and Yuma's Pendant. Leaving ones that also increase the maximum number of possible minions summonable would also help increase your damage output; the best choice for this would be Yuma's Pendant, as it increases your maximum minion count by 2 while also increasing summon damage by 15%.

If you are playing as a Thrower, the Guide to Expert Throwing - Volume III is a phenomenal accessory that provides a sizeable increase to your throwing weapon's DPS, and should be used. If you are playing in Expert Mode, another accessory to consider would be the Lich's Gaze. Because the set bonus of White Dwarf armor activates on critical strikes, having the ability to always inflict critical hits from True Strikes complements well with armor's ivory flares. Similar to the Philosopher's Stone, the Lich's Gaze can be quickly equipped just to activate True Strikes, then exchange it for another accessory to take better advantage of the guaranteed critical strikes.

If you are playing as a Bard, the Auto Tuner is a helpful accessory that has a chance to increase your empowerment level, which can help better support you and your allies, especially with empowerments such as Life Regeneration or Damage Reduction. This is further supplemented with the wide range of empowerments provided by the Terrarium Autoharp. The Headset's effect works in conjunction with Shooting Star armor's set bonus, making it attractive, but the benefits from it are fairly lackluster, making this accessory only really viable if you have no other option. Similarly, using a Music Player may help if you are lacking a weapon that provides a certain empowerment.

Weapons
For this final battle, you should have the best of the best weapons for whatever weapon type you wish to use. These will namely be weapons obtained from the Lunar Events and Terrarium Cores. Any weapon you plan to use should have the best possible modifier to increase their power further. In general, having at least one weapon that excels at single-target DPS as well as at least one weapon with strong piercing capabilities is extremely helpful for the encounter.

Do note all of the primordial spirits, as well as the Expert Mode-exclusive final phase, are immune to all debuffs, meaning weapons that would be normally used for weakening enemies, such as Golden Shower or Prime's Roar, will have little effect in this fight, only effecting the minions spawned during the fight.

Melee
Swords with projectiles are adequate choices, but generally lack the DPS or piercing to be exceptional. At minimum, the Influx Waver works, but stronger choices including the Essence of Flame, the Meowmere, and the Star Wrath are preferred.

Spears lack the effectiveness to be recommended over other melee weapons. Of the two to be considered, the North Pole does not deal high enough damage, while the Terrarium Spear's projectile is too slow to be effective in the fast-paced battle, often dealing only minimal amounts of damage. The right-click rapid stabbing is more effective, but also brings you much closer to the danger zone of the battle.

Boomerangs are fairly strong for this fight, though the only viable option for dealing damage is the Terrarium Hyper Disc. With correct positioning and speed, the hyper discs can damage The Primordials while returning, allowing for additional damage than simply throwing them directly at the primordial spirits.

The only Flail that should be considered should be the Solar Eruption. That said, the Solar Eruption is arguably the best melee weapon to use for this battle, in part to its high damage, respectable range, and unlimited piercing. It is particularly strong against the final phase of the battle in Expert Mode.

Yoyos are powerful choices against The Primordials, but are not quite as effective against the Expert Mode-exclusive phase, as yoyos generally lack the capabilities to easily deal with the number of swarming enemies, making dodging more difficult. The best choice is the Terrarian, but The Sick Throw also works if you did not obtain it from the Moon Lord.

The two other melee weapons that should be considered are the Daybreak and the Quake Gauntlet. They both serve as an alternative to the Terrarium Hyper Disc, trading DPS for more range, making them great choices for dealing with the final primordial spirit once the other two have been defeated. In particular, they excel at combatting Slag Fury, who tends to remain behind the other two. However, in the boss’s Expert Mode-exclusive final form, these weapons lose efficacy. The Daybreak cannot pierce, making it difficult to hit Dream Eater when it performs its Lucid Bubble attack, while the Quake Gauntlet’s slow use time and stationary area of effect, coupled with the boss’s high movement speed hamper it severely.

Ranged
Your main options for Bows are the Terrarium Longbow and the Phantasm. Between the two, the Terrarium Longbow does not consume arrows and is capable of inflicting Terrarium Backlash onto minions summoned by The Primordials, but its overall DPS is much lower than the Phantasm. As for arrows, the only real option would be Luminite Arrows, as they are the ideal compromise between high damage and some piercing capabilities.

By far, the best Gun against the first stage of the fight is the Emperor's Will, as its bullets follow the cursor of the player and deal very high damage, paired with Luminite Bullets or Terrarium Pulser Shots to deal very high damage quickly to each Primordial. Other effective guns to use against The Primordials are the Terrarium Pulse Rifle and the S.D.M.G., should you happen to obtain it from the Moon Lord. These two guns offer high damage and firing speed, but more importantly, a tighter bullet spread. This may not seem like a major benefit, but this frees up the choice of bullet from just Chlorophyte Bullets. While using them along with a weapon with high spread, such as the Vortex Beater, works fine for either Normal Mode or the first phase of Expert Mode, the large amount of piercing from Luminite bullets are almost essential for the Expert Mode-exclusive phase of the battle due the sheer number of minions constantly being spawned. For this purpose, it's best to utilize Chlorophyte or Crystal Bullets for the first phase of the battle, then swap to Luminite Bullets when Aquaius disperses into bubbles, as well as when the final phase begins in Expert Mode.

Finally, Launchers are a decent choice due to their high damage and explosion radius, being helpful whenever the enemy crowds together. In terms of DPS, the best Launcher is the Terrarium Bomber, boasting high damage and firing speed. The Snowman Cannon, while low in damage at this point of the game, is helpful for Normal Mode or the first phase of Expert Mode thanks to its homing rockets. The Electrosphere Launcher's lingering hitbox is excellent for dealing damage against minor enemies, such as Aquaius Bubbles. The last launcher to consider is the Supersonic Bomber; this is a decent alternative to the Terrarium Bomber if you do not want to obtain the necessary materials for Terrarium Cores. Like the Terrarium Bomber, the Supersonic Bomber has a high fire speed and damage, and an even higher velocity, but its overall damage is not as high as the Terrarium Bomber's. The only rocket that should be used are Rocket IIIs, as they have the highest possible damage for launcher ammunition while not risking blowing up your arena.

Magic
The Ancient Flame, dropped by the Lunatic Cultist, is a fantastic weapon to use against The Primordials. It deals above average damage, its shotgun-esque firing style work well in tandem with its explosion splash damage whether it is against a single target or a group, such as with Aquaius Bubbles. Unfortunately, the Terrarium Sage Staff is much less useful; despite having automatically homing shots, it generally is much weaker than the Ancient Flame, and cannot inflict Terrarium Backlash against most of The Primordials.

In terms of single target DPS, the Nuclear Fury is a decent weapon. Although its novae do not pierce, they deal large amounts of damage and automatically aim towards enemies. Another recommended spell tome to use is the Lunar Flare. It deals fantastic damage, and the constant barrage of lunar flares combined with their splash damage makes this weapon excellent against crowds of enemies, especially against the Expert Mode-exclusive phase.

That said, the Last Prism is by far the best magic weapon to use against The Primordials, and is arguably the most powerful weapon against it in general. This is in part to its astronomical DPS and natural piercing capabilities, allowing it to shred through all phases of the battle. Its only downside is its high mana cost, but this can be partially alleviated with accessories like the Mana Flower, as well as Mana Boosters from the Nebula armor set bonus.

Throwing
Throwing is a very powerful class to use against The Primordials. In terms of main damaging-dealing weapons to use, the choice should be limited to either the Terrarium Ripple Knife and White Dwarf Cutter. Both of these two throwing knives deal very high damage per second, but between the two, the Terrarium Ripple Knife cannot pierce, but deals more direct DPS, is non-consumable, and is able receive a modifer, whereas the White Dwarf Cutter is able to pierce enemies and has a slightly higher critical strike chance, which complements the White Dwarf armor set bonus.

Besides these weapons, other items that are highly recommended would be ones that supply the player with the ability to teleport, such as the Rod of Discord or Technique - Shadow Dance.

Bard
Symphonic weapons are decent for the battle, but many of them are fairly weak, limiting the number of viable options. That said, the empowerments granted are an excellent aid to support either you or your allies, making Bards more focused on survivability than direct damage.

Unfortunately, none of the available Wind or Brass instruments are recommended for this fight, as even the strongest options lack enough damage to be effective, and the primordial spirits are all immune to debuffs.

The Shooting Star Blast-Guitar is the best String instrument available for this fight. While its heavy metal riffs pierce, the main source of damage when utilizing this weapon comes from the falling star fragments. With proper timing and spacing, it is possible to have several riff's worth of falling star fragments all land on The Primordials, easily ripping through thousands of the bosses' health. If you will be using this weapon, ensure your arena has several blocks to allow the riffs to bounce for the falling star fragments.

The Green Tambourine, despite being available before Plantera, is regardless the best Percussion instrument for this fight. Although its base damage is subpar at this point of the game, there is no limit to how many can be on screen at once, allowing constant damage against all the primordial spirits, even when recovering inspiration. Unlike the Terrarium Hyper Disc, The Green Tambourine also possesses a much higher velocity, allowing it to better keep up with the spirits for more damage. Because of this, The Green Tambourine is able to out-damage many late to endgame Bard weapons. In addition to this, its Life Regeneration II empowerment significantly bolsters your survivability.

The Terrarium Autoharp is a solid weapon to use. While its damage is fairly low, its sound pulses automatically home, and provides a wide variety of empowerments, which complements Shooting Star armor's set bonus well. With all seven empowerments, the player's symphonic damage will be increased by 56%, and inspiration regeneration by 14%, significantly increasing your damage potential. The Sound Sage's Lament is difficult to use effectively, but if you are able to land the five stave surge at the end, you can deal extreme amount of damage. The easiest way to use it is to bring the cursor directly next to the player. Finally, the Sonic Amplifier is a decent choice, wielding high damage, life shielding, and an excellent Life Regeneration III empowerment. However, its left-click attack drains inspiration fairly quickly, and its right-click attack is too slow to be an especially effective piercing option.

Other Items
While armor, accessories, and weapons are the most important issues, a few other key items can definitely help out for the fight.

Having a Light Pet equipped that has other abilities, such as the Twinkle or Demo's Guidance, can give you the upper end in the fight without any penalty whatsoever. The Twinkle is usually preferable, as Demo's Guidance only grants buffs that can already be given by placed tiles.

Similarly, a suitable Mount may help increase your maneuverability. The Slimy Saddle and Super Anvil have notably higher downward acceleration, and the Tome of the Void Gazer's Chariot or the Magic Broomstick allows for more refined area movement. By moving in a figure-eight formation, the battle in Normal Mode or the first phase of Expert Mode can have its difficultly significantly reduced. A special mention should be made for the Shrimpy Truffle from Duke Fishron's Treasure Bag; if you set your arena to include some water such as by using water-filled Bubbles, it easily outpaces many other mounts while also boosting your damage.

The Rod of Discord can be used to instantly teleport, which helps avoid certain dangerous attacks.

At this point, you should be using Super Healing Potions due to their high health restoration. Aside from recovery potions, you should also have some variety of the Cook's Food for extra healing. While you can use the mapped to the same button as your  to use both recovery options at once, doing so will also double the length of Full Stomach, so it is preferable to have it in your inventory slot to be easily accessed. Life Fruit Platter restore the highest amount of health, but you may also want to use Mean n' Green Stew if in a world with Corruption rather than Crimson to get the Rage buff along with Wrath. Mana Delight restores mana rather than health, so you may wish to use them if you plan on using magic, summon, or healer items. If not, Super Mana Potions will suffice for mana-restoring needs.

Alongside health restoration, buff potions are highly recommended for the battle. Make sure to have some form of resisting Poisoned if using Heartreach Potions, due to Omnicide's Tainted Hearts.