TreeMina AU in the world of Avatar: The Last Airbender. Long before the Fire Nation went all conquest crazy, the water tribes came into massive conflict with each other. While the North agreed to let the South keep their own government, the current chief of the water tribes started imposing more and more on the South. Eventually, this led to an all-out war.

The North has one massive power on their side: the avatar, Lamina. She only recently returned from her travels around the world in search of masters to teach her how to wield the elements and came home to assist her tribe in the war. Of course, the leader of the North have not been honest with their people, as they know most would not support it. Everyone has been told the South tried to be completely independent through force, without even bothering to talk about it or negotiate. Since the Southern style of waterbending is more aggressive than the defensive Northern style, the Southerners are clearly more combative. If they’re given their independence, who knows what they’ll do! One day they’ll take over the North and attack other nations, so they have to be stopped! And since the South attacked first, the North has justification for a hostile takeover as they siege the South non-stop. Of course, the truth is that the North attacked first, but only a small amount of people knows about that.

Meanwhile, in the South, there’s a young waterbender named Treech. He’s not much of a fighter, though he’s proficient in the Southern style of bending. His skill mostly lies in healing. His attacks are his defense, keeping the enemy away for long enough so he can heal whoever needs it and get them to safety. If it’s just him, he’d rather run away or hide than fight, but when the lives of others are in the balance he won’t rest until he’s saved them. It is that quality that ends up getting him noticed by the biggest threat to his people.

During a new siege, Treech runs and hides as troops pass through the settlement, laying waste to his beautiful home. Finally he comes across a sort of safehouse, where injured and non-benders try to stay out of the line of fire. Treech is the only bender there who is well-enough to heal, and does his best to help everyone. That is, until they’re found by a group of Northerners, including a certain someone. Treech realizes he’s the only one that can do anything, and if he doesn’t everyone there will die, so he tells them to stay put and runs upstairs. From the window, he attacks the Northerners from above and starts fighting them. While he manages to take out the three or so waterbenders, he stands no chance against the avatar on his own and he knows it. But he can’t let her touch the helpless innocents inside, so he fights. Despite holding out far longer than expected, she eventually manages to knock him out.

Lamina knew she was doing the right thing, but the boy was around her age and looked so desperate as he fought her that she couldn’t help but doubt. But the captain was certain soldiers were hiding here, and she wouldn’t let anyone endanger her people. She could spare the boy, though. The others were unconscious, so once she was done inside she’d hide him somewhere safe. No one had to know. Except once she busts down the doors of the house, she sees nothing like what she was expecting. Instead of terrifying soldiers and battle plans, Lamina sees a group of civilians, mostly children, almost all of them with minor injuries. One of the more gravely injured ones has a massive wound on her side, water diluting the bloody pool underneath her, and that’s when it hits her. That boy hadn’t attacked them out of anger or a lust for blood, he’d been protecting these people. He’s been using his bending to heal the wounded! Lamina looks around the room once, before stepping towards the wounded woman. Everyone looks terrified, then confused when she heals the wound. Perhaps the captain was misinformed? It says nothing about the South as a whole, surely, but every group has its innocents! So she leaves, but just as she leaves the house the boy outside wakes up. He panics, and as Lamina tries to calm him down a new squad of Northerners comes around the corner. She tries to stop them from attacking, but they don’t listen. Before Lamina can do anything, the boy has brought up a massive wall of ice to block their attacks and yells at the civilians to run, before stomping on the ground. The ice cracks around them, and before anyone can react Lamina, the soldiers, and the boy all fall as the ground collapses underneath them. Then there’s darkness.

When they wake up, it’s just Lamina and Treech in the rubble. At first, Treech slinks into a corner and is fully prepared to fight her, but she calms him down and then they talk. At first, Lamina refuses to believe the North are the agressors here, but Treech shares some of his experiences and tells her to stay in the South once the siege is over to see the world like he does. To look at this conflict from the eyes of a Southerner. So she does. No one bats an eye over Lamina not returning to the ships because she often makes her own way back, so once the Northerners have left she pulls her hood up to hide her identity and Treech leads her around the city. She’s never returned to a settlement soon enough after a siege to see the extent of the destruction the North caused, and she’s horrified at what she finds. Treech leads her deeper into the city and when she asks why, he tells her he wants to show her something she needs to see. The depths of what the North will do to keep control over them.

Back in the cave, they’d argued briefly about what caused the war, with Treech stating it was the North pushing for more and more power over them while Lamina says they attacked first and need to be kept under control. When they finally reach the center of the settlement, Lamina is horrified to see the rows upon rows of injured. Treech leads her around as he heals as many as he can, with Lamina joining him while she works through the shock. Finally, he pulls her to the side so they can talk privately.

“Does that look like keeping us ‘under control’ to you?! Because all I see is needless cruelty!”

“I-“

“And when did we attack you? Because I don’t remember such a thing happening!”

Treech offers to show her some other Southern settlements so she can see that this isn’t a one off, this is the status quo. Lamina is starting to realize maybe she doesn’t have the full story and agrees, starting their journey across the Southern water tribe. During this time, the two start as grudging companions only working together for their own reasons (Treech trying to make the strongest warrior of the North realize what she’s contributing to so his homeland isn’t destroyed. Lamina trying to figure out what’s happening because as the avatar she must do what’s best for the world, not just her own people, and she cannot let her bias lead her). Over the course of their journey, they evolve to friends and then start to fall in love with each other. By the end they’re simping for each other and Lamina realizes that the North is being lied to by their leaders. So she comes home and tries to convince them to stop and while most of the army listens to her after some convincing not everyone cares. A small group of soldiers goes to attack the south again and Lamina and Treech rush back to stop them and there’s a climactic final battle. When Treech is nearly killed Lamina loses it and enters the avatar state, at which point she becomes a living, unstoppable nuke of nature. The North is forced to surrender and the peace between the tribes is restored. The South regains the power to govern themselves for the most part and the two lovebirds get to happily live out their lives.