In Death Note, the theme of the consequences of one's actions is portrayed through the main character Light Yagami's descent into darkness as he uses the Death Note to eliminate criminals. The series shows how each action and decision he makes has significant repercussions, leading to a chain of events that ultimately result in tragic outcomes for himself and those around him. The consequences of his choices are explored in depth, highlighting the moral and ethical dilemmas that arise from wielding such power. Ultimately, Death Note serves as a cautionary tale about the destructive nature of unchecked power and the importance of accountability for one's actions.