10 Heroic Movie Characters Who Actually Didn't Affect The Plot
10. Luke Skywalker - Return Of The Jedi
Though Luke Skywalker is instrumental in the end of the first/fourth Star Wars movie, by the time the final, and best series addition to date comes around, he's basically an over-emotionally invested sidekick in his own story. He's so focused on his attempts to redeem his father, who is irredeemable whether or not he acknowledges that his son actually matters to him more than the destruction of the galaxy, thanks to all of the badness he's already committed, that he's largely superfluous, other than as a distraction.
Had Luke not been present during the events of Return Of The Jedi, the ending would still have gone exactly the same: Lando would still have been the real hero by blowing up the Death Star despite almighty odds stacked against him (including not being helped by the ONLY PERSON IN THE GALAXY TO HAVE BLOWN UP A DEATH STAR before,) Darth and the Emperor would still have died, and everyone would still have ignored the fact that the fall-out from the explosion would still have ruined Endor anyway.
So, in apparently fixing his relationship with his estranged father, all Luke does is ensure that his death devastates him a little, despite the fact that there is no fate for Vader that wouldn't be an enormous terrible cop-out other than death. And while the galaxy rejoices about the death of the worst people in the history of their history, Luke probably goes off to write poems about never really knowing his father, or spectacularly failing to mount a "he wasn't really that bad" PR campaign.
It's not like Luke would ever have been able to convince anyone that Vader wasn't all evil, as it was just his word against the collected experiences of everyone else, and some mighty strong evidence to the contrary. So he's literally the only one to gain anything from that whole section of the film, and had it not occurred we wouldn't have had the reductive impact the twist in the tale had on the greatest villain in all of space movie history.