Nick entered the Fiend of Darkness while holding the rope.
The first thing he felt was that he was suddenly being pulled forward, and he used the rope to realign himself with gravity's new direction.
The next thing he felt was the familiar pain of being under the Nightmare's influence.
Since Nick had his eyes closed, he couldn't see what was happening to him.
He could only feel it.
He felt something sharp and burning entering his chest.
He felt his muscles being pulled from his bones.
He felt acid encompassing his body.
The Nightmare's creativity was immeasurable, and it often combined different tortures.
Nick gritted his teeth and did his best not to release the breath he was holding.
But it was difficult.
It was so very difficult.
The pain was just so bad.