Ultranium/Ignodium

Ignodium is a Post Moon Lord boss intended to be fought after Moon Lord alongside.

While Ignodium is alive, the Guardians phase 1 music will play in phase 1 of the fight and Guardians phase 2 will play in phase 2 of the fight.

Summoning
Ignodium does not spawn on its own and is summoned by using a in the Underworld.

Behavior
This topic is a Work in Progress

Phase 1
Ignodium repeatedly charges at the player, firing a slightly homing fireball with each charge. Every four charges, he will fire one unique attack in a fixed cycle.


 * Pauses in place and launches five large fireballs that explode into rings of smaller fireballs after travelling a certain distance.
 * Slowly follows the player and fires three rings of homing fireballs.
 * Stops in place, charges up and glows before firing two rings of fire bolts.
 * Stops in place and fires three gradually widening spreads of flame blasts.

Once Ignodium is reduced to 50% HP, he briefly goes invulnerable and enters Phase 2.

Phase 2
Ignodium starts using a newer, enhanced attack pattern.
 * Chases the player and fires eight large fireballs that explode into rings of shots.
 * Stops in place and summons seven fireballs from under the player, telegraphed by orange beams.
 * Charges five times while shooting a homing fireball with each charge.
 * Fires a fast, dense spiral of fireballs.

Phase 3
At roughly 12.5% HP, Ignodium briefly goes invulnerable, stops moving normally, and releases a desperation attack.
 * Summons three rows of orange shards from below, telegraphed by orange beams.
 * Fires three orange shards at the player before releasing a very fast and dense spiraling barrage of shards.
 * Teleports above the player and repeats.

Trivia

 * This boss replaced Hades in the 1.2 update.