Set in the ATLA universe. Everyone is human, Splinter still adopted the boys.
Master Splinter shook his head fondly as he watched his sons play in the river. They had always been a happy little band, traveling from one area to the next. Splinter had thought fondly on how, just last month, their nomadic family and met another and how they'd managed to get lost together in a swamp. Fortunately, some of the locals came and helped them out, and even let them stay at their campgrounds. They had also showed Leonardo how to bend the water in plants to use them in his fighting, giving the eldest a good deal of activity. But, Raphael was beginning to go stir crazy with only small sections of land to bend; and his youngest seemed fearful, like he thought he might send the marsh up in flames if he bended. And so, after a good long week in the marsh, they continued on towards the South Pole.
There was much less fear here, as he watched his youngest and eldest bending their respective elements at each other to create a steam bath. After a while, Donatello walked over and laid himself out on a blanket to dry off in the sun. "Hey, father, do we have any tea left?" Donatello asked, looking at their basket of food.
"We have jasmine and dandelion. Which would you like?" Master Splinter asked, pulling out the two tea canisters.
"I am in desperate need of dandelion." Donatello sighed, stretching himself out.
"Michelangelo, would you warm some water for tea, please." Master Splinter called, setting one canister away, and pulling the teapot and some cups from a bundle.
"Coming father." Michelangelo replied, running over to grab the teapot and take it upstream for some water, meanwhile Master Splinter dug a small pit and filled it with sticks. Michelangelo returned at a slower pace, not wanting to spill too much water, and set the teapot in the unlit kindling before breathing a small flame into the pit. Donatello filled the strainer with dandelion tea, and set it aside for when the water was hot enough.
"Thanks Mikey." Donatello chirped from where he had flopped himself over so that the sun hit his back.
"It's what I do." Michelangelo beamed, then began rummaging through the basket. "Father, do you have an idea of when we'll next find a town?"
"The next town is only half a day's walk." Master Splinter informed him, having studied the map just hours ago. "We will camp here for the night and early morning, then set out near midday."
"Good, because I'm going to go fight Raph for the last of the fire flakes." Michelangelo stated, smiling up at his father before running back to the river with a shout of "Hey boulder-brain!" Leaving his father to shake his head at the antics of his sons.
"I think I'm going to watch this one from back here." Donatello commented, grinning as he sat up to watch as Leonardo set up the fight for a fair beginning. Raphael went with his usual beginning move, stomping hard enough to rattle the earth under his opponent's feet, while simultaneously freeing large portions dirt from the earth to weaponize. Michelangelo, however, didn't use his usual counter move, but did a flip forwards, sweeping fire along with his feet to break Raphael's concentration. Michelangelo never actually hit them with fire (well, not on purpose anyways), rather he mostly used it defensively or as a distraction. Raphael aimed one of his dirt clods at Michelangelo, who dodged it and sent a sizable ball of fire from his fist to destroy the other one. It took a full ten minutes of Raphael moving dirt and Michelangelo destroying the masses before Raphael got frustrated enough that Master Splinter had to step in, declaring a stalemate and having them share the fire flakes.
Donatello and Leonardo were stifling their laughs as they watched Raphael's face grow deeper and deeper shades of red from the fire flakes. Raphael said he liked the bite they had, Michelangelo said they were crunchy with just a touch of heat to them. "What're you doing Don?" Leonardo asked, trying to peer over his brother's should to look at Donatello's invention journal.
"I've been working on finding a way to make travel easier, and making the packs lighter when they're full." Donatello explained, willfully showing his brothers his sketches. "I've been thinking along the lines of making miniature hot air balloons, but the problems with that is that Mikey would have to keep heating them up. Then I thought about forgoing that and just finding a way to put wheels and handles on the packs, but that would only really work out in towns and cities with proper roads. If we tried dragging wheeled bags through the woods, we'd get caught on everything."
"I wouldn't really mind heating the balloons if you want to give that a try." Michelangelo offered with a shrug of his shoulders.
"Thanks. But the idea is that it would be less taxing on all of us, and I don't want you to get burnt out." Donatello chuckled at his own pun before continuing, "And anyways, I'm currently thinking of just redesigning the straps to make them easier for our backs to carry."
Raphael leaned back on his elbows to relax into the dirt, "Once again, Donatello the book-bender is watching our backs." He joked.
"Well, when you don't have bending to look out for yourself, you have to actually use your brain." Donatello joked back, toeing his brother's knee and sticking his tongue out.
Master Splinter chuckled and shook his head as his sons poked fun at each other. Again he wondered what outsiders must think when they happen upon his family; a Northern water master and his sons, hailing from the South Pole, Ba Sing Se, Ohmashu, and the fire colonies in their respective birth order. It wouldn't matter what they thought, he decided, for they had all the elements of a family.