True friends are few and far in between for most Targaryens. It's something with which Rhaenyra, Alicent and Viserys all struggle in House of the Dragon, and it became an issue for Daenerys on many occasions in Game of Thrones.
The mother of Dragons got lucky when she found Missandei of Naath. After Daenerys set her free, Missandei chose to stay with the queen, becoming her most trusted advisor and friend. As her role in Daenerys' life grew, viewers had more opportunities to get acquainted with the strong, kind and loyal Missandei, usually through the transparency and eloquence of her words.
"My People Are Peaceful. We Cannot Protect Ourselves."
Season 8, Episode 2
By the final Game of Thrones season, fans already had a pretty good understanding of who Missandei was as far as character and personality went. She was soft and patient and at times demure in the way she carried herself, but that didn't only develop from her experiences.
Speaking to Grey Worm about wanting to return home, Missandei gave a little more information about the people she came from: "My people are peaceful," she said. "We cannot protect ourselves." It's no surprise that Missandei came from such a peaceful people. She herself is much of the same but definitely has a strength that could and had offered her protection.
"I Think That I Am Not Fit To Have An Opinion On These Matters."
Season 5 Episode 5
Missandei and Daenerys had a strong bond, but it took time for Missandei to unlearn the slave mindset that she was pushed into after many years under masters.
Daenerys trusted Missandei and her judgment, even turning to her for advice on the handling the fighting pits in Meereen. Not thinking she was fit to offer such counsel, Missandei said to Daenerys, "Your Grace, I think I am not fit to have an opinion on these matters." Thankfully the queen quickly shit down that notion, reminding Missandei that as someone who has lived on both sides of such a war, she is more qualified than anyone to offer insight.
"Who Said This?"
Season 6 Episode 3
With such a wealth of knowledge, Missandei's intellect is something that may be subtle but is always prevalent in the way she carries herself. She was always soaking things in and learning from her experiences and the people around her. Being one of the smartest Game of Thrones characters, Tyrion was one of those people.
Picking up on Tyrion's cleverness, Missandei often listened with intent to learn but still with skepticism of the new player. She was hesitant to take him at his word, but on the occasion that he said something particularly insightful, she couldn't help but jump at the opportunity to learn something new asking, "Who says this?" Tyrion of course had pulled the quote out of his own mind, which only fueled Missandei's confusion of his true character.
"The Masters Speak Only One Language. ... I Know It Better Than My Mother Tongue."
Season 6 Episode 3
So much of who Missandei was is unfortunately rooted in her experience under several masters as she grew up. It wasn't what she wanted but it's what she knew. Coming from that place, she was able to bring an insight to the queen's counsel that the others couldn't when facing issues in Daenerys' absence.
Her full statement to the rest of the queen's counsel, several of whom contributed to Daenerys' downfall, was, "The Masters speak only one language. They spoke it to me for many years. I know it better than my mother tongue. If we want them to hear us, we must speak it back to them. May it be the last thing they ever hear." It was one of her most poignant lines that showed her often hidden strength.
"Not Long Enough To Understand."
Season 6 Episode 4
While Daenerys was gone for Meereen in Season 6, Missandei showed a lot more of who she was in her interactions with Tyrion, Grey Worm, and Varys. When Tyrion made a deal with the slavers, he tried telling Grey Worm and Missandei that as someone who had been a slave for a single day, he could empathize with the slaves.
Saying this to two people who had grown up in chains of their own showed Tyrion's misunderstanding of his privilege and Missandei's response of that's "not long enough to understand" showed not only how deeply she herself could empathize but how she was using those experiences to better serve the people in a way that Tyrion could never.
"Naath. I'd Like To See The Beaches There."
Season 8 Episode 2
Before the final seasons of Game of Thrones, Missandei's home of Naath was only mentioned on occasion but in seasons seven and eight, more details were shared. When she and Grey Worm discussed leaving Westeros after the season eight battle Missandei suggested going to Naath saying "I'd like to see the beaches there."
Missandei had stuck by Daenerys' side but in Winterfell, she was so obviously misplaced. In saying that to Grey Worm she made it clear that while she was loyal to her queen, she still wanted to find somewhere that felt like home. It was an obvious setup to make her impending death that much more devastating, but it was a pure moment that showed she was more than just a loyal confidant to Daenerys.
"Many Things."
Season 7 Episode 4
Daenerys was not blind to the relationship that budded between Missandei and Grey Worm over the years. Though the two tried to deny it and were often too shy to admit their feelings to one another, the years of built attraction, respect, and friendship finally came to a head in a romantic moment in season 7.
When her friend and queen picked up on the possible change in their relationship, she asked for clarification on what happened between the two, but Missandei simply grinned and said "many things." It was a very coy response for the usually open character but perfectly showed her happiness about how her relationship with the soldier had developed.
"Valar Morghulis."
Season 3 Episode 3
One of the first characters to say the iconic Game of Thrones phrase "Valar Morghulis" was Missandei. The term of course meaning all men must die was a reminder of the mortality of men and the inevitability of death.
For Missandei to say the phrase so early on, it established her mindset and understanding of the unpredictability of the often tempestuous world around her. However, it became a moment in Game of Thrones history when Daenerys responded to the statement saying "all men must die, but we are not men."
"She's The Queen We Chose."
Season 7 Episode 4
Jon Snow was apprehensive to trust the Daenerys, but he knew that he needed her and her resources to win the battle in the North. Jon had already formed an opinion on her after a few interactions, but it wasn't until Missandei shared opinions of her own that he got real insight into who she was.
Talking to Jon and Davos, one of the best Game of Thrones side characters, Missandei said "she's not our queen because she's the daughter of some king we never knew. She's the queen we chose." She says it with pride and resignation perfectly summing up her contentment in her choice to serve the queen that the genuine belief and loyalty she placed in Daenerys' hands.
"Dracarys."
Season 8 Episode 4
Only a single word came from Daenerys' most loyal friend and confidant when she was given a moment to share her last word before the mountain executed her: "Dracarys."
Daenerys had tried to avoid using her dragons to burn down the King's Landing but in those powerful last words, Missandei showed strength and spoke directly to Daenerys, leading Daenerys to make one of her dumbest decisions. Fans may have been expecting something more along the lines of "Valar Morghulis" but the almost out of character line only helped conclude Missandei's final development into the stronger person she had become at Daenerys' side.