Light Yagami's pursuit of justice is initially motivated by his desire to rid the world of criminals and create a utopia where crime no longer exists. As he becomes more morally compromised and starts resorting to extreme measures, such as using the Death Note to kill criminals, his motivation shifts towards maintaining his power and sense of righteousness. Light becomes convinced that his actions are necessary for the greater good, and he becomes increasingly consumed by his own god complex, believing that only he is fit to decide who deserves to live and who deserves to die. His pursuit of justice transforms into a quest for control and dominance, driving him to continue his morally questionable actions despite the consequences.
