Chaos
From the Castlevania Wiki, the Castlevania wiki
Chaos is the source of all of Dracula's powers. When Soma entered Chaos' room, Chaos chose him to become the next Dark Lord. He stole all of Soma's souls and fought him in the form of a ball with 3 statues on it. Each had a different attack. The red statue would hold all of your Bullet Souls, and three easily deflected crystals will shoot out. The blue statue would hold all of your Guardian Souls, and would transform into a gargoyle demon that rushes at you, which can be easily avoided. The yellow statue would hold all of your Enchant Souls, and would summon a targeting reticule to lock on to Soma that steals his MP. Destroying all statues would give Soma all of his souls back.
When Soma beat it, it transformed into its true form. Chaos' final form is a black orb in the middle of the room. The only way to effectively defeat it is to destroy the 4 demon eyes in the corner of the room. When those are destroyed, you can deal the normal amount of damage to the core. The core will summon needles & homing projectiles to attack you. A serpent made out of bones, similar to Death's second form in Harmony of Dissonance slithers around the room, dealing massive damage if the player comes into contact with it. When Soma beats Chaos, it shatters. If Soma loses, a cutscene will show a start of a battle betwen Julius and Soma. Chaos is one of the three enemies in the game that does not drop any souls, along with Julius and Graham. Interestingly, Chaos originally had an enemy list entry, which showed a picture of Chaos not used in the game. However, the creators took the entry out of the game, making it unable to get the entry without hacking.


