Ultranium/???

"Aldin's true form has been unleashed!"

??? is a secret Post-Moon Lord intended to be fought after. He doesn’t require Erebus to be defeated, however the boss is very difficult and it is recommended to have Erebus gear before attempting it.

Summoning
??? only spawns by clicking the ??? option while talking to the with a  in your inventory. The Reality-Bending Shroom is given by The Keeper after showing him the 7 secret mushrooms.

Behavior
This topic is a WIP
 * ??? will spawn 3 seconds after the ??? button is clicked, all of his attacks are in a fixed pattern:

Phase 1

 * Will hover above the player and stop after a few seconds to rain down giant stars that split into a barrage of smaller stars;
 * Will stay in place and release a bunch of cosmos bolt that home into the player and stop a few seconds later;
 * Will stay in place and fire 7 lasers in the player’s direction;
 * Will summon a bunch of galaxy orbs near the player’s position;
 * Summons 3 orbs that fire lightning at the player.
 * Summons circular laser in a fixed pattern
 * Summons giant stars in a circular fixed pattern
 * Summons rings of cosmic star around the player that move towards the player (This is done 4 times in a row with mild delay, Each set has more stars)
 * After this, the cycle will repeat.

Phase 2
Phase 2 begins once ??? gets to 50% HP, he will hover above the player for a few seconds and cause the screen to shake, afterwards he will use these attacks, still in a fixed pattern:
 * Will cause a ring to appear to indicate where he’s gonna teleport to, a moment after teleporting he will release a star that splits into several smaller stars, the last star will be a giant star and will release many more stars;
 * Will stay still and cause an exclamation mark to appear on the left, after a second a few laser walls will come from the direction the mark was in, these can be easily dodged by standing still and jumping. Running away to the opposite direction of the exclamation mark will make the laser wall fires rapidly
 * Summon 3 giant homing ball of cosmos that periodically grow in size and explode into a circular cosmic blast bolt
 * Shoots 4 laser from his body in a X pattern and summon 6 waves of circular cosmic blast bolt
 * Will repeat the laser wall attack but from the right side
 * Will repeat the laser wall attack but from the top
 * After this, the cycle repeats.

Phase 3
Upon reaching 25% HP, ??? will become invincible and stand still again for a few seconds and then hover above the player:
 * After a few seconds of hovering above the player, ??? will cause a storm of stars to rain down which splits into lots of smaller stars and finish the attack with 3 giga stars that cause a giant star explosion. This attack is only used right after ??? enters his 3rd phase and after the attack is finished he will become vulnerable;
 * Hovers above the player and stands still, causes several orbs to circle around him and then releases several cosmic blast bolt around him to attack the player. This is the same as one of the previous attacks, just harder;
 * Fires a dense circular stream of deathrays that circles around multiple times, running out of flight time before the attack ends can be very fatal. When ??? is using this attack ??? will create a small circular arena that will trap the player to prevent escape;
 * 2 exclamation marks will appear on each side of the player and then 2 laser walls will appear, same as the previous attack but come from both side;
 * Causes an exclamation mark to appear above and below the player, same as previous attack but up and down;
 * Rains 4 giga star from the sky;
 * Summon 4 homing ball of cosmos around him;
 * Release a bunch of cosmos bolt around him 3 times;
 * Summon 8 lasers around him in a cardinal direction alongside the arena and many small stars around his body;
 * After this, the cycle will repeat.

Tips

 * It is highly recommended to have a big arena before attempting to fight the boss, as the amount of projectiles requires a good amount of room to dodge.
 * Having a Rod of Discord helps immensely, as some attacks have tight gaps and are hard to dodge without one if proper preparations weren’t made.
 * It is also a good idea to move Aldin to a house nearby your arena instead of in your main base, as you only have seconds to get away before ??? spawns. Npcs may die if Aldin isn’t moved.

Trivia

 * This boss is based off of the concept of how Aldin was supposed to be the final boss of the mod.
 * Every attack sound effect is taken from Asriel Dreemurr’s fight from Undertale.