The pipeline from the Nightmare Realm to the spaceship was very long, and Sheyan was actually already more than three kilometers away from the Realm. He guessed that the spacious entrance he came to after sliding down from his private space was already quite a distance away from the main body of the Nightmare Realm.
But this did not weaken the strong sense of oppression Sheyan felt when he looked back in the slightest!!
Roughly speaking, it would be like if Sheyan was a twelve or thirteen year old boy, standing in the Central Plaza and looking up at the 373-meter-high Central Building. It was that kind of pressure.
(TL: The building: http://images.skyscrapercenter.com/building/centralplaza_ext-main_(c)dennislau-1.jpg )
The dizzying magnitude seemed to occupy all his senses in an instant, making him feel so small, while the object standing majestically in front him like a king felt like it was the entire world!