Primordia

Primordia is a late Hardmode Boss that is summoned with a Forgotten Insignia in the desert. The materials for the summoning item are obtained from Primordial Thralls that appear during a Sandstorm after the defeat of Golem.

Behavior
Primordia possesses two phases split across two forms, the second one begins when you reduce her health to zero.

Phase 1

 * Primordia will rest in the area summoned and will not move, she will restrict the area the player can move in with Shield Orbitals.
 * Attempting to escape the area will move the player back, and colliding with the shield orbitals will deal damage.
 * She will begin with three attacks, and gain more attacks the lower her health gets.
 * Solar Burst: She fires 8 solar beams outwards in an even pattern 3 times, indicated by a telegraph.
 * Rune Barrage: Several solar runes manifest around Primordia, and then fire at the player.
 * Fire Shot: A stream of fiery projectiles is released from Primordia's eye.
 * Targeting Beam: Fires a beam that predicts the player's movement 8 times (below 80% life).
 * Sweeping Beam: Fires four beams outwards that sweep the area clockwise or counter-clockwise (below 60% life).
 * Primordial Meteor: Primordia's eye releases yellow fireballs upwards that fall down and make her following attacks harder to dodge (below 40% life).
 * Solar Wave: Primordia will summon two sigils to her left and right, which shortly after summon giant light pillars that sweep the area on the corresponding side (below 20% life).

Phase 2

 * Primordia breaks free from her grounded body and begins flying around above the player, firing projectiles.
 * Fire Shot: Fires five flame projectiles at the player.
 * Sweeping Beam: Charges up energy and fires a beam straight downward 3 times.
 * Primordial Meteor: Fires meteors upwards that fall down.
 * Eye of Ra: Summons sigils around the player that explode after a while.
 * Solar Wave: If the player runs into the same direction for too long, Primordia will summon a sigil in the direction the player is running to that summons a light pillar sweeping the opposite direction the player is running into, forcing them to change direction (expert mode only).

Trivia

 * The song that plays during the battle is Altera Solem, composed by Turquoise and LordCakeSpy.
 * It is confirmed that most of the attacks that Primordia utilizes in her fight are inspired by Hollow Knight's final boss.