Sun Wukong was very confident in his abilities, otherwise, he wouldn't have dared to cause Havoc in Heavenly Palace five hundred years ago.
However, Sun Wukong equally understood that in this vast world there were not only many magical treasures but also numerous odd demons and ghosts, all possessing very unique abilities.
If used well, it was not strange at all to defeat enemies of a higher level through restraint, achieving victory despite weaker strength.
Sun Wukong's Cultivation Level was extremely high, already reaching the peak of Taiyi True Immortal, and coupled with the Vajra Indestructible Body, and his natural aptitude, he could even battle with a Great Luo Golden Immortal, as seen in his fight with Master Leizhen.
But Sun Wukong was very clear that if there was anything that could restrain his abilities, Nightmares could be considered one of them.