Light Yagami's reliance on logic and reason contributes to his downfall as it leads him to develop a god complex, believing he is the ultimate judge of justice. This overconfidence in his own intellect blinds him to the ethical implications of his actions and causes him to become increasingly ruthless and detached from humanity. Additionally, his reliance on logic makes him underestimate the emotional and unpredictable nature of his opponents, ultimately leading to his downfall as he is outmaneuvered by those who understand the power of emotion and empathy.
