The Last of Us perhaps has the best-crafted story and characters in all of video game history. Both games and the Left Behind DLC present vastly different perspectives and personalities. The first entry and the DLC explore both Joel and Ellie's losses of loved ones and their eventual father-daughter attachment as a means to reconcile those losses. Fans expected more of the same from The Last of Us Part II, but instead, that game explores the idea of revenge and how it can blind you to other important matters in life. The Last of Us Part II also introduced new characters for the player to follow.
Ellie and the newly introduced Abby deal with revenge and the consequences of it in obsessive ways. Through each of their journeys, the two learn how alike they are and because both are wonderfully written characters, the player realizes this as well. In the eyes of the player, Abby transforms from a ruthless villain who brutally kills Joel into someone that the player realizes is just like Joel, and Ellie for that matter.
Some would say that The Last of Us Part II has no good people and bad people, but only survivors. This gives the game a depth that deals with the consequences of our violent actions without having to put labels on the people in the story. Few other games have successfully explored this notion. Uncharted 2: Among Thieves touches on this when the villain likens Drake's violence in the game to his own. In a way, the gun-toting, neck-breaking hero is no different from the killers he's fighting against.
To this point, Abby, Ellie, and Joel are all the same. They are all survivors and have experienced significant losses and formed strong bonds. Not one of them is more evil or good than the others. In fact, it is suggested in both games that Joel has done a great deal of horrible things to people in order to survive. The writing of The Last of Us Part II should be commended for its expertly crafted character studies, especially regarding Abby and the other newcomer Lev.
Abby and Lev grow to love each other, much like a brother and sister might, and because of the stunning writing, the player becomes connected to the new duo as well. This connection grows so strong that in the final act of The Last of Us Part II, the player can't help but feel love for Abby and Lev as they did for Joel and Ellie. The phenomenal impact that The Last of Us has is that it presents a broken world, filled with all kinds of survivors and their stories. It is not a franchise that should only have one main character. The Last of Us is set up perfectly for players to see all kinds of characters and their respective journeys.
Abby and Lev must carry this franchise forward because Joel and Ellie's story is finished. The two capable survivors have intriguing backstories that could be further explored in The Last of Us Part III. Abby and Lev resonate with many people, and their presence in the gaming world is essential and relevant. They can be the voices for underrepresented groups that society has shunned. They each have the depth that makes for greatly compelling characters, their will to survive is admirable, and the ending of the second game suggests that their journey is far from over.