Dream Rise House.
The door to Section IV was thrice thicker than the other sections. Unlike other sections, the door was made from a combination of six metals and stones.
Adamantine, Gallium, Vajra, World-mending stone, and two other unknown metals, which didn't even exist in Earth's record, were used to create the door and the surrounding walls.
Both Kiba and Claudia have spent a lot of efforts and resources to reinforce Section IV. Everything to prevent the outer world from destruction.
Now, though, the door has retraced and the section was open. Terrifying waves of energy, in the form of violet streams, boomed out, carrying the power of extermination.
The high-density force field covering the corridor and other sections, along with extremely durable metallic walls, prevented the energy from seeping outside.