The writers of Game of Thrones had to adapt George R. R. Martin's expansive world of Westeros to the screen. Of course, not every character made the final cut. Would the show have been better off including all of these characters? Possibly. It's hard to know for sure. Yet there's one character from the books who definitely should have been included. Adding this character would have likely made the show's ending more satisfying. And the writers definitely needed that. After killing off so many popular characters, including Daenerys Targaryen (Emilia Clarke), it really wouldn't have hurt to add one more. Especially if this character had survived to see the end of the show, it really would've been interesting.
Of course, the writers of Game of Thrones must've had their reasons for cutting this character, as interesting as they might be. It could be that this character is not essential to the overall plot of the story, even in the books. Or it could be that the writers just thought this character wouldn't fit with the story they were telling. Yet, some fans must have missed this character's presence. And it wouldn't have hurt the writers to add one more intriguing character. Especially since fans were disappointed by the ending, it would have been nice to have another cool character survive. And this character definitely would've had their fans. Therefore, those disappointed by the fates of other popular characters such as Daenerys and Jaime Lannister (Nikolaj Coster-Waldau) might have found someone else to root for.
This character also might have given voice to some of the fans' thoughts on the ending if they had lived to see it. Of course, that's never a guarantee on Game of Thrones. Possibly, this character would have been mistreated or written out. Or mistreated and then written out, like Daenerys. Yet if they had lived, it's hard not to believe that fans would've been a tiny bit more satisfied with the ending of the series. So who is this mysterious character who would've helped Game of Thrones avoid such a fast downfall? It's Arianne Martell. Yes, that's right, in the books, House Martell is a lot bigger. Arianne is the oldest child of the current prince of Dorne, Doran Martell, and therefore the heiress to Dorne. In the books, she has two brothers, Quentyn and Trystane.
The show, however, only showed Trystane of that entire generation. In the books, Arianne is not close with either brother, preferring to spend time with her uncle Oberyn's daughters, known as the Sand Snakes. One of her closest friends is Tyene Sand, as they're the same age. The two young women are like sisters and spend a lot of time together. Arianne is described as cunning and adventurous. She has a temper and will use any tools at her disposal to get what she wants, including her beautiful looks. She is a rather important character in the books, in that we see Dorne from her point of view. It's somewhat surprising that Game of Thrones would cut such a crucial character. Perhaps the writers know something about her role –or lack thereof– in the books.
However, it's hard to imagine that she is so unimportant that she could be written out entirely. In the books, Arianne briefly plans to crown Myrcella Baratheon as the Queen of the Seven Kingdoms. It might have been interesting to see this storyline play out on Game of Thrones. Unfortunately, her plot is foiled by Doran, and Myrcella loses an ear in the process. Doran then locks Arianne up but eventually, he summons her and asks for her help. He also reveals his actual plans to his daughter, how he plots to get revenge for the deaths of Elia and her children when King's Landing was taken from the Targaryens. As part of this plan, he secretly arranged for Arianne to marry Viserys Targaryen and become Queen of the Seven Kingdoms. Of course, Viserys is now gone, so Doran's plans had to shift.
His new plan is for Quentyn to marry Daenerys and for Arianne to inherit Dorne. Doran sends Quentyn to Meereen to meet Daenerys, and Arianne is glad to know her father's plans. This storyline, too, would have been interesting to see on Game of Thrones. Arianne could have made a good ally for Daenerys, and Quentyn too. Unfortunately, poor Quentyn is not as clever as his sister in the books and is destroyed by one of Daenerys' dragons. Yet, such a thing might have been changed in the show. In any case, Arianne might have been the type to speak up after Daenerys met her fate. She would've made a powerful ally or enemy for the Mother of Dragons, depending on how the story went.
However it would have gone, Arianne also would have been another strong female character on a show desperately in need of them. Especially after Daenerys' passing. If she had been around in the show to inherit Dorne, at least that would have been a part of the ending fans could root for. Some fans, of course, might have been satisfied with Sansa becoming Queen in the North. Yet other fans might see this storyline as too sudden, especially as Sansa's role, in the end, mainly was to be an antagonizing force to Daenerys. If one of Daenerys' powerful allies had survived and inherited a kingdom of her own, it might have appeased Daenerys fans just a little bit. Especially since Arianne wanting to rule Dorne is a significant part of her character in the books.
She is also very similar to Daenerys in that both of them are powerful women existing in a world largely ruled by men. However, Dorne is slightly different from the rest of Westeros in that regard. Dornish law allows women to inherit, to be heiresses, etcetera. It is far ahead of the rest of the country with its more progressive ideas on women and on sexuality as well. Arianne would have been another example of an independent, powerful woman allowed to exist on her terms. And that might have appealed to some fans. Of course, not every fan will agree that Arianne's inclusion would have improved the ending of Game of Thrones. For some fans, nothing could do that. In contrast, others will see nothing wrong with the conclusion of the series.
Everyone has different tastes. Yet it would've been nice to see the Game of Thrones take on this intriguing character.