Kapitel 961: Can't Complain.

Ragnarok was even able to smile and reminisce about the past. "Reminds me of the ice trial during the trial of heaven."

The monotonous environment of pure white reminds him of the first trial in the trial of heaven that Gehaldirah attended. He was supposed to keep moving through the cold temperature and bleak ice landscape for an unknown distance. 

The temperature was much colder than this and he had to survive for years in that small world of ice. His current situation is similar to that ordeal but it is nowhere as difficult. 

He said to himself, "If I could survive the trial of heaven, then I can definitely survive this. I will see where it ends."

He is no stranger to dreary and boring situations so he wasn't discouraged by the lack of stimulus in his environment. He continued to fly for months on end without stopping. It is but a fraction of the years he spent in the ice trial.