The entrance to the Chaotic Realm is located within Floating Garden. When you first try to enter, you will be attacked by Julius Belmont.
Julius, as the vampire hunter, will initially attack with the Vampire Slayer. He will also jump into the air to perform drop kicks, and also make slide attacks against the ground. However, unlike other enemies, he does not inflict collision damage. Julius is even resistant to the Claimh Solais; to defeat him, you may want to use Laevatain, but any weapon that he doesn't resist (anything other than Holy, poison, rock or curse.)
When he takes sufficient damage, he will float up into the air to charge a powerful cross attack. You will need to run away as quickly as possible, or you will be killed by contacting it. Afer the initial show of force, he will use his subweapons, including the axe, holy water, and thrown cross.
Once he is defeated, he will confess that he was holding back. Soma will make arrangements with Julius in case he fails.
Chaotic Realm[edit]
The chaotic realm is a mix-and-match of all the places you visited previously. In general, there is one major route, with the side paths leading to either save points, dead ends, or a single item room.
There is one very important item in this zone - the Chaos Ring. It is available only when you collect 100% of the souls. This ring drastically increases mana regeneration, allowing you to indefinitely use magical abilities.
The final door is sparkling with electricity, but you can enter it without issue. Be sure to save the game before entering.
Chaos[edit]
After the introductory cutscene, you will fight against Chaos.
The first form will prevent you from using your souls, and locking them into three sections. The piece holding the red orb will create three projectiles and launch them at you. The piece holding the blue orb will transform to a creature and charge. The piece holding the yellow orb will try to drain your MP. The best method to defeat Chaos is to use the Claimh Solais, and to try to release the red orb first. When you do, you should be able to launch more powerful attacks that remove the other two enemies.
The second form has a bone snake circling around randomly. The snake will occasionally launch an attack, but that's not the only thing to worry about. The center will occasionally launch four orbs to the corners, which then try to close in on you (which are repelled by attacks). Also, a set of thorns will appear in a circular pattern. To defeat this second form, destroy the eyes at the corner to lower the defense of the middle section, then attack the middle until it is destroyed.
If you have trouble with the thorns, then watch the way they appear. Once the circle of thorns is complete, they will launch in the same order. Simply walking under the center will let you avoid this attack.
Once you defeat chaos, you will unlock some new features for the game, including the ability to play on hard mode.