Sokka

(All characters in this story are 6 years older than in canon, so Aang is 18, Katara is 20 etc)

When Team Avatar arrived to Gaoling, Sokka was busy shopping. At one particular store, Sokka was trying to figure out if he should buy a certain purse or not. After mulling it over a bit, and Katara and Aang getting impatient, he hands over the money and purchases the purse.

Upon picking it up, Sokka noticed that it felt heavier than he expected, almost as if something is in it. He opened the purse and found a book inside. He looked over to the other two, but they were busy talking about finding an earthbending teacher for Aang. He decided to open it on his own in order to see what it was. On the first page he was greeted with a message.

The world runs on rules. Schools and companies have their handbooks. Towns and cities have their nobility. Even countries have their laws. You spend all day following rules. Wouldn't it be nice if you could be the one writing the rules for once? Now you can. This is the Rulebook. Simply put the name of an organization and write your rules. Any rule you can think of will be followed by everyone in that organization.

You can write Old Rules and New Rules. People will treat Old Rules casually, like they've been around forever. The world will even change to accommodate Old Rules as you write them. On the other hand, New Rules only go into effect once you've written them down. People will still follow them, but they may express nervousness, embarrassment, excitement, or other emotions about them. Anything written in this book can be erased by the original writer.

There are only 2 caveats about the powers of this rulebook. You cannot write a rule that kills someone such as X person can no longer breathe, and you cannot make an old rule if it retroactively being enforced brings back the dead.

Sokka was surprised by this note, and certainly wanted to test it out. He was skeptical and thought it was a joke, but if it was real… how would he even test it?

“Well, if this book is real, at least I can erase what I write,” he said to himself as he wrote his first organization: Gaoling.

Old rule: All purses sold in shops are bright red.

It wasn’t anything major, just a way to see if this book actually worked. Sure enough when he looked at the purse around his arm, the brown purse was now bright red. Satisfied, Sokka erased the rule and put the book back in the purse. He’d need to think of a good rule to help them win the war.