Light Yagami's actions in Death Note have a profound impact on the broader societal structures and institutions within the series. His use of the Death Note to eliminate criminals leads to a shift in power dynamics, as he becomes both feared and worshipped by some as the self-proclaimed "god" of a new world. This creates a sense of unease and uncertainty within the society, with people divided over whether his actions are justified or morally reprehensible. Additionally, his actions serve as a catalyst for the introduction of new rules and regulations by authorities to combat his vigilante justice, leading to increased surveillance and a crackdown on dissent. Ultimately, Light's actions not only disrupt existing societal norms but also expose the flaws and vulnerabilities within the system, highlighting the complexities of morality, justice, and power.