Storm Weaver

Storm Weaver is a post-Moon Lord boss and is one of the Sentinels of the Devourer. It drops Armored Shells, which are a crafting material required to craft the Cosmic Worm.

Spawn
The Storm Weaver does not spawn on its own and requires the player to summon it with the Rune of Kos, causing it to rain. It must be summoned in the Space layer.

Behavior

 * It will begin to rain when summoned into battle, and much like other bosses who have a similar effect, it will not occur during the Boss Rush event. Storm Weaver has segments in total.
 * The Storm Weaver does not enrage if the player leaves the Space layer, and can be fought anywhere once summoned.

Phase 1

 * The Storm Weaver's body and head are nearly immune to all damage; the only way to deal significant damage is to hit its tail, which has 0 defense.
 * Damage dealt against the tail is multiplied by 10.
 * The body will reduce the piercing power of all projectiles to 1.
 * The Storm Weaver will only attack you if you aren't on the ground, similar to the Crawltipede.

Phase 2

 * The Storm Weaver will shed its armor and reveal the flesh underneath; it will have no defense whatsoever in this phase, but compensates with higher speed, 500% extra health and increased damage.
 * The body reduces the damage of piercing projectiles; the more the projectile can pierce, the less damage it will do.
 * Storm Weaver will now constantly chase the player, even if they are near or on the ground.

All Phases

 * Summons orbs that fire bolts of lightning at nearby players.
 * Lightning bolts occasionally rain from the sky and attempt to hit players while Storm Weaver is alive. The number of bolts that rain at once is increased during Phase 2.

In Revengeance Mode

 * Storm Weaver moves faster.
 * Lightning inflicts Electrified.
 * Periodically turns a dark blue color, which gradually turns into a lighter shade. Then Storm Weaver charges directly at the player, summoning lightning from above as it does so.
 * The lightning will be shot from the direction Storm Weaver is charging from.
 * Charges more often as its health decreases.

In Death Mode

 * Has more segments and is physically larger.
 * Damage dealt against the tail in phase 1 is multiplied by 3 instead of 10.
 * Charges more frequently.

Resistances

 * All Phase 2 Storm Weaver segments take reduced damage from non-minion piercing projectiles. Projectile damage is divided by the number of times it pierces and infinite piercing deals 50% damage.
 * All segments reduce damage from grenade-type projectiles by 80%. A list of affected projectiles is below.


 * On top of this, all segments take:
 * 90% damage from the Scorched Blades from the Shattered Sun.
 * 75% damage from the Molten Amputator and its Molten Globs.
 * In addition, the Molten Amputator's pierce is updated to 6 (9 if stealth strike) if it contacts a segment.
 * 50% damage from the Pristine Fury, Elemental Axe and Dazzling Stabber Staff.
 * 40% damage from the Wave Pounder's explosions.
 * 10% damage from the Stardust Dragon.

Tips

 * Stay on the ground and don't panic if you're almost dead. Panicking will often lead to you trying to outrun the Weaver, which is not possible.
 * Mobility is the key to this battle. Although it's hard to outrun the Weaver, using dash abilities or the Rod of Discord or Normality Relocator can save you from the massive damage caused by its head.
 * Gravity Normalizer Potions can be used to counteract the low gravity in Space allowing easier maneuverability.
 * For the first form use piercing weapons and weapons with a large blast radius, as these can help hit the tail of the Weaver. You can easily out-maneuver the first phase with Seraph Tracers by circling around the Storm Weaver while being in space. This method also helps dodge the Weaver's summons and fired laser beams.
 * The orbs that Storm Weaver fires do not deal contact damage, only the lightning bolts themselves.
 * Homing weapons are recommended for Phase 1 as they can easily hit the tail.
 * The Elemental Shiv is recommended for this fight due to the homing capabilities and the amount of projectiles it produces.
 * The Telluric Glare does good damage to Phase 2 with its piercing and ignoring immunity frames.
 * Nuclear Fury is an excellent choice with homing capabilities allowing it to easily hit the tail in Phase 1 and swarm weaver with typhoons in Phase 2.
 * The Shattered Sun does good in Phase 1 as it homes in on the tail, but Molten Amputators excel in Phase 2.
 * Elemental Axes are an excellent choice quickly dispatching the Storm Weaver.

Trivia

 * Storm Weaver's theme is a segment from Servants of the Scourge, which was composed by the artist DM DOKURO.
 * This theme contains a motif from The Devourer of Gods' theme.
 * If the Calamity Music add-on mod is disabled, Boss 3 will play instead.
 * Despite being a boss, Storm Weaver will not drop a Treasure Bag in Expert Mode.
 * According to the lore, The Devourer of Gods is the same species as the Storm Weaver, meaning that it likely has the same type of flesh underneath its armor.
 * Prior to the 1.4.5.004 update, the Storm Weaver used to spawn Stasis Probes when hurt, similar to The Destroyer's spawning Probes.