Korach: True Oved Hashem

Korach's two hundred and fifty men were warned that the earth would swallow the rebels, and they went ahead anyway. Rashi asks whether they were fools and answers that they "sinned with their souls," which sounds like it answers nothing. The Netziv notices that the two groups are mentioned separately and die differently, one by fire and one by the earth. What does that tell us about their motives? Rabbi Asaf Prisman adds a mashal of a king, a loyal servant and an offer too good to refuse.