I haven't even reached the end of Nirvana in Fire yet but I love it so much, I know this is one drama I will rewatch over and over to take lessons from it.
Leaving aside the points that most reviewers will mention - the acting, music scores, cinematography, script, costumes, etc, which are indeed all fantastic & high quality, - for me, the main attraction is how this story captures human nature in all its facets.
The story writer/screenwriter has a deep understanding of human nature and has studied it. In this drama, you will see how people can have everything and lose it through greed, foolishness, and stupidity. Others can start from relatively nothing, yet gain everything through wisdom, hard work, strong friendships & good advisors.
Although we know this already & have seen it in countless dramas, Nirvana in Fire depicts it so well. Although it's a revenge drama, it doesn't feel like it because the aim of the main character, Mei Changsu, is not just to get personal revenge for the destruction of his family but to improve the future of his entire country. He seeks to put a good leader on the throne to secure his country and this noble aim raises the drama above a personal revenge plot.
Along the way, we watch several people displaying all their personal flaws & strengths and we hopefully learn from them. Here are just 3 of them.....
The Emperor is childlike and immature - susceptible to flattery, generous when in a good mood but very paranoid and easily becomes moody & angry. His lack of personal self-control leads to many problems in his reign.
Prince Jing, one of the Emperor's sons, is righteous, loyal, and almost unflinchingly honest. He hates duplicity and wants to be straight forward in all his actions. But he is naive and rigid in his self-righteousness, which sometimes creates unnecessary troubles. So we learn that even though honesty, loyalty & righteousness are to be admired, one must mix in caution & flexibilty, the ability to adapt to circumstances. To be too rigid invites being broken by life.
Mei Changsu, the main lead, who plays the wise adviser & Kingmaker, is an absolute joy as a character. He is a man who has been refined in the fires of pain and suffering early on in life and out of his experiences, he has fixed upon this goal of putting a righteous Emperor on the throne. To achieve his aim, he has learned to be patient yet decisive when needed; resolute, cunning, and a great planner. He is a born military leader and strategist; inspiring loyalty & devotion in his men. He has discernment & wisdom - he sees through the superficial and into the true motives and nature of people.
There is little romance in this drama but a lot of intrigue and suspense that will keep you desperate to know what happens next. You will never be bored as you keep cheering for good to outwit evil and righteousness to reign.