King fights alongside the Seven Deadly Sins against the Six Knights of Black, demonic threats to the Sky Palace and its Celestial inhabitants. He wields the Spirit Spear Chastiefol, employing its third form's "Fossilization" ability to petrify the demon Atollah, causing the demon to shatter upon impact. Later, King and fellow Sin Diane execute a coordinated "Combined Technique: Cross Shooting," defeating the demon Galla. His combat role emphasizes established abilities and teamwork against the antagonists.