Light Yagami's actions in the series "Death Note" lead him down a path where he becomes consumed by his own sense of justice and power. As he continues to use the Death Note to eliminate those he deems as criminals, his initial intentions of creating a better world become twisted by his own arrogance and desire for control. This gradual transformation ultimately results in him losing touch with his original sense of honor, as he becomes more focused on maintaining his power and supremacy rather than upholding a moral code.