Author's note: This is the first letter. It is from Azula to Fire Lord Ozai. I know that some of the facts are wrong but I did that on purpose. I think this is exactly what Azula would write after the season 2 finally. She took all the credit and still thinks she killed the avatar!
To the Fire Lord:
Dear Father,
I am pleased to inform you that, due solely to my own brilliance and your imperial support, Ba Sing Se is no longer in the possession of the Earth Kingdom. This grand city, that has avoided invasion 100 years, has fallen, under your superior reign. I have taken the city from the inside out. Due to the less then hostile take over the city was not destroyed and, as such, is ready for Fire Nation occupation.
Also I have discontinued an attempt on the Fire Nation. The Earth Kingdom's council of five had been informed of the upcoming solar eclipse and, most astoundingly, had also come to the conclusion that we will be immensely disadvantaged during the period when the sun is not visible. I have imprisoned the men involved with this dastardly plot and no free person has the knowledge of the eclipse. On to the subject of the Avatar; I followed your instructions, father. I waited until he was in the avatar sate then delivered the fatal strike. He fell. I saw with my own eyes. The avatar will never rise again. Unfortunately I am unable to send you his cold body because his waterbender guard took his body with her as she fled. My pursuits were halted by my meddle some uncle and blundering brother who escaped there imprisonment for a few moments, only long enough to provide the avatar's friend with a distraction. Both of them are in my jail.
I am eagerly awaiting your governor so that I may swiftly pass on power from myself to him and personally escort my defeated brother and uncle to you. On the way I will pick up the avatar's friends and the avatar's body. I'm sure the army could benefit from a flying bison addition. Also who better to be your personal servants then the daughter of an Earth Kingdom noble (Bai Fong no less!) and the Southern Water Tribe's leader's only two children? I'm sure they will obey your every command after being forced to watch what you do to uncle and brother; the five of them have developed quite an attachment to each other.
I will be returning soon.
Your Ever Loyal Daughter,
Azula