Manipulation of emotions and psychological manipulation play a crucial role in Light Yagami's strategies in the anime series "Death Note." Light uses these tactics to control and influence others to achieve his goal of creating a new world order where he is the ultimate judge. By manipulating people's emotions and thoughts, Light is able to manipulate them into doing his bidding and furthering his plans without directly revealing his true identity as Kira, the one responsible for the deaths of criminals. This manipulation allows Light to maintain his facade as a model student while secretly orchestrating his grand scheme.