One of the things that really compels me about Mei Changsu and Xiao Jingyan’s relationship in Nirvana in Fire is the way they complement each other in their quest for the throne and justice for those they’ve lost, and how they each change toward what’s better suited for what they need to do.
In the case of Xiao Jingyan, the need for change is very obvious; he needs to get more flexible, more willing to play the politics, and less hotheaded, all of which does happen during the course of the show. The Xiao Jingyan of episode 2 when we first meet him or even the one of episodes 36/37 when the confrontation with Xia Jiang about Wei Zheng happens wasn’t ready to handle the emotional roller coaster of the reveal in episode 49 or the final confrontation with the Emperor in 52/53.
Mei Changsu also changes during the course of the drama. It is quite obvious that ever since the massacre he has only been living for the purpose of getting justice for his family and the Chiyan army, and he has determined that to achieve this he needs to put aside the softer sides of his humanity and be the cold strategist who only thinks of the goals ahead, ready to make even ruthless sacrifices. We see him struggling with it but pressing on at the aftermath of Jingrui’s birthday party and the death of Xie Qi. As he goes, he guides Xiao Jingyan toward the kind of conduct that’ll allow him to survive the power struggle, but also shields him as much as he’s able, intending to take all the morally questionable burdens on himself.
The interesting events happen when their intentions and boundaries clash, how it progresses and which one ends up yielding. Xiao Jingyan will only bend so far, there are boundaries he will not cross even if it is strategically unsound to stick to his principles, and with the Wei Zheng issue it is Mei Changsu who ends up having to change his mind and take a path that’s not wise but that he actually wants to take (but wouldn’t have if not for Xiao Jingyan insisting). With it, he allowed himself to become a bit more Lin Shu once again, lessening the perfect image of that cold strategist he had maintained. It is the most prominent event of this kind, but not the only one, because Xiao Jingyan keeps reminding Mei Changsu of who he was (without knowing it of course), and it is really hard to keep being just the calculating strategist when your best friend holds your memory as one of the key elements of his moral compass, and keeps bringing it up.
So, as the drama progresses, Mei Changsu’s heart doesn’t fully harden in the way he’d expected it to, he keeps the heart of Lin Shu alive inside himself, Xiao Jingyan keeps to his moral limits, and in fact these characteristics allow them to finally get the retrial of the Chiyan case started. The strategist’s way would have been what the Emperor with his suspicious mind speaks out at the beginning of episode 53. At that point, Xiao Jingyan holds literally all the power and could force the case more thoroughly. He could in fact force his father to abdicate the throne the way the Emperor suggests, and had he ordered the Emperor physically restrained when he took up the sword, no one would have questioned him. Yet, he chose to put himself in danger instead, to stand there on the path of the sword without flinching and asking for reason instead.
Later, when Mei Changsu speaks with the Emperor, he appeals to his humanity, appeals on behalf of those gone that the Emperor used to hold dear. I don’t think he could have been as efficient as he was if he had managed to harden his heart fully during the course of the drama. It’s not the strategist speaking there, it is a nephew, a son, a leader of men lost that’s stating his appeal, and it works because it’s real. His words come from the heart, and that’s why the Emperor believes him when he says Xiao Jingyan will not lose his way on the throne, and finally allows the justice he asks for.
The writing in the drama is so wonderfully competent, the way it is obvious the Chiyan case couldn’t have been overturned without both Mei Changsu and Xiao Jingyan, not just in their roles as a strategist and a prince, but as the people they are and the relationship between them, the way they complement each other and help each other become better, a sum much bigger than its parts.