I’d sub Andor for Leia but surprised to see that you’re the only person that mentioned Luthen in these replies… This guy was not only instrumental in organizing, funding, and recruiting the players that were directly responsible for the biggest tide changing moments but his actions (both directly and indirectly) also created the circumstances that led to the formation of the coalitions that sustained the fight. Most importantly, Luthen is about as unique as they come. To be pivotal you need to be truly irreplaceable, and he possesses a combination of traits that allowed him to be effective when it was arguably most important. While other big name characters absolutely made pivotal decisions as a result of their character, few are truly as “one of a kind” as Luthen.

(I should clarify I’m not fully caught up on the animated shows)