This is my interpretation of how Bolin joined up with Kuvira and the Earth Empire. Enjoy.
Bolin slung his pack over his shoulder as he made his way down the road. Pulling out his water bottle he took a deep swing of the refreshing liquid and let out a content sigh. It had been a year since Zaher and the rest of the Red Lotus had been captured and thrown in prison and everyone else had something to go back to when it was over. Mako had his police work, Asami had Future Industries and Korra went back to the South Pole to heal after the Red Lotus poisoned her. Everyone had something except Bolin. Even his new girlfriend Opal was rebuilding the Air Nation and helping to stabilise the Earth Kingdom.
So, deciding that he needed to find his own path, Bolin packed his things, took whatever money he had left and despite everyone's protests, set off to find his path.
That was a year ago.
Since then he traveled all over Earth Kingdom, he had been everywhere, from learning how to sand bend in the Wong Shi Tong desert after he saved a local tribe of sand benders from bandits with his lava bending to spending some time incognito in Zaofu to master the fine art of metal bending. Now he was wandering helping towns with bandits and aiding the people of his nation a little at a time. He still got letters from home every now and again. Letters telling him how great Mako's detective work was going, letters and newspaper articles all about future industries from Asami and he and Opal always made sure to send letters to each other regularly.
Still, Bolin was getting restless, but he knew that his path would find him soon.
A crash sounded in the distance, and dust rose into the air. Bolin turned his head before running full speed towards the source. He knew the mountains here didn't have land slides unless they were made to, and only bandits ever made landslides.
bending the earth beneath him in to speed himself up Bolin moved faster and closer to the scene of the attack. pushing himself so that he spanned the height in mere seconds he summited to observe the situation. A train he recognised as one from Zaofu was jammed by rocks, trapping it and blocking its path. Bending a stone board and moving quickly down the side of the mountain, Bolin allowed a small smile to cross his face, as it did whenever he was about to stop bandits.
Quickly catching up with the closest bandits around halfway down the mountain, Bolin bent the earth around him to unbalance the bandits. As the earth beneath them shifted and quacked, in some cases large pillars of earth rose up to stop the bandits in their tracks. As more and more of the outlaws noticed the young bender disabling their members they turned their attention from the train towards the youth.
Bolin skidded to a stop and the base of the mountain next to the tracks and dived to the left, barely dodging a boulder thrown his way. Lowering into a stance and jabbing with his left arm, Bolin sent an wave of earth, forcing one of his opponents out of the fight by knocking him out. Five more bandits toke their turns as more rushed to aid their team mates, hoping to overwhelm Bolin with numbers.
Bolin dodged to the side, ducking and evading the rocks and jumping over unstable earth and rock pillars. Perfoming moved he learned from an earth bender in the province of Wan Bolin encased three of the bandits up to their necks in the ground before slamming rocks into the other two, knocking them off their feet and sending them to their knees.
By the time he dealt with them over a dozen bandits had shown up. One of them, the oldest and most probably the leader stepped up.
"Well, well boys, look what we got here, a goodie goodie who thinks he can save some people." The group laughed obnoxiously, finding their boss' comment funny.
Bolin's face crunched up slightly, showing his annoyance at their disregard of him.
"Well kid, you put up a good fight, now leave us with any money of valuables you have and we might let you go." Bolin knew the guy was lying, but played along for the fun of it.
"Oh thank you oh glorious bandit, king of the people I just beat, I'll definitely give you everything I own… right after I kick you and your friends' butts."
The smirk on the lead bandit's face disappeared, replaced by a frown and then a sneer.
"Alright kid, you had your chance, get him!"
The bandits rushed forward, but Bolin just rolled out of the circle and bent the earth around them to capture them, three of them were caught but the others were quick enough to move before getting caught.
Bolin, in an effort to finish the fight quickly, lava bent the ground around the bandits, forcing them onto a makeshift island as the molten rock closed in on them.
The leader stared at Bolin, disbelief clearly written on his face.
"You… you're him, the lava bender who roams the Earth Kingdom."
Bolin nodded, a smile now gracing his face as the bandits grew more and more nervous and more and more hot. The lava had not receded.
Suddenly clapping was heard from behind Bolin, who whipped around and bent the earth to throw. Behind him stood a woman with black hair, green eyes, a small mole on her right cheek under her eye, an elegant face and formal military dress with stripes of metal all over the top half of it. Bolin didn't recognise the person wearing it but he knew if they were in one of Zaofu's trains, they were either friend, or about to be in some serious trouble.
"Hello Bolin." The woman said, a serious expression on her face that betrayed no emotion.
"You probably don't remember me, but I was with you and your brother when Avatar Korra gave herself over to Zaheer and the red lotus. I'm Kuvira"
Bolin's eyes lit up in recognition.
"Oh yeah, Kuvira, nice to see you again. What have you been doing?"
"I was chosen as the the interim for the Earth Kingdom until it is stabilised. My team and I have been traveling the nation, trying to reorganise it after the death of the queen."
"That's great, I'm sure you'll get the place back under control in no time. Do you need some help with the bandits."
"No Bolin that's fine. We have soldiers who can deal with them. Would you like to come inside?" Kuvira gestured to the train. "It must be tiring, walking all across the kingdom."
"It is… wait, how did you know I was traveling the Earth Kingdom?"
"Come and have tea with me, and I'll explain everything."
Bolin felt nervous about following her, but wrote it off. She was here to help the people of the Earth Kingdom, why shouldn't he trust her?
Inside the train where was calming green walls and elegant metal furniture. Banners of a silver symbol for the Earth Kingdom hung from the walls, one of the symbols of the metal clan, and a tea set was laid out. Kuvira sat down at one end of the table, and motioned for Bolin to take a seat at the other end. Pulling the seat out sitting down, Bolin waited as Kuvira poured tea into both their cups, adding a slight amount of sugar to her's and taking tentative sip of the hot liquid.
Bolin reached for his own cup and began to drink, with much less elegance or class as he drank the way he would drink anything.
They both finished their tea and Kuvira set her cup back on the saucer.
"Bolin, the reason why we didn't interfere with those bandits, the reason you are here, is a simple one… we wanted to know if you were willing to fight for the people of this Kingdom"
"What" Bolin replied, totally lost.
"They have names for you, you know, 'The lava nomad', 'the miracle worker', 'the liberator'. You've been helping the people of the Earth Kingdom. I want to give you the chance to do more."
Bolin looked confused
"What do you mean?"
Kuvira took a deep breath, looking the 18 year old right in the eye, she laid down her proposal.
"Join my army, you could make a difference, a bigger difference, as a part of something bigger than yourself. If people could see that even the 'lava nomad' joined up with us, it would help us immensely. What do you say? Will you join us?"
Bolin looked shocked, he had never received an offer like this before. Still, could he do what she wanted, could he go around and be this mascot, or whatever she wanted him to be.
"I would love to, but I can't. I have stuff that I have to do and as much as I want to I can't help you right now."
Kuvira didn't seem the slightest bit disappointed with his refusal, which surprised him because she seemed so set on having him.
"Still, will you come with us to the next town, we can drop you off and make sure nothing happens."
Bolin didn't see anything wrong with that, so he shrugged and nodded.
"OK, do you have any extra closes, or a washer I can run my stuff through?"
"Of course, Zhu Li please take Bolin's possessions to a room."
"Wait Zhu Li, as in Varrick's assistant Zhu Li."
"The one and only." An eccentric voice called out from the end of the hall.
"Varrck!" shouted Bolin, both happy and angry to see the eccentric inventor.
"Hey there Bolin, isn't this great, Kuvira's got us all working on this whole earth kingdom project but" Leaning in close so that only the two and everyone else could hear them. "I've been thinking about using magnets. They're the next big thing in technology, but the beifongs think I'm 'Crazy', and 'Out of my mind' just because I blew up a couple of Zaofu blocks, but I just see the future. Zhu Li!"
The assistant slid in from the side of the room.
"I want a new air vent system in the 'Platinum Men' by this time next week, and get those ideas from my last storm session through to research and development. I told you last time, I want prototypes by next week."
Kuvira, seeing the direction the conversation was going, stepped in and distracted Varrick before he could rush Bolin off to some other part of the train.
"Varrick, Bolin and I still have some things to talk about, please go and check up on the rest of the train."
"You got it boss lady… Zhu Li! Lets go."
"Sooooo, about that."
"Don't worry about it, Varrick is nothing if not an eccentric. More importantly, we are just about to enter the capital of the next province, walk with me."
The two walked along the train as it neared the town and the station. One of the soldiers handed Bolin a uniform with a symbol for private on it.
"Uh Kuvira, what is this?"
"The best we could do, get dressed."
By the time Bolin had gotten on the uniform and folded up his old cloths, the train had stopped and Kuvira was waiting impatiently at the doors.
"What took you so long?" She asked, a slight edge in her voice that was disappearing as he stood there.
Bolin pulled his smooth, suave moves.
"Hey, it takes time to perfect this look, its not just one, two done."
Kuvira didn't laugh, instead she gave the young earth bender a hard glare.
The doors opened and light flooded Bolin's vision. In front of him he could see citizens, men women and children. All looking in wonder at the metal beast before them. One man, a governor by the looks of his dress, was standing at the front of the crowd.
Kuvira walked out of the train and stopped in front of the governor, with a neutral voice she spoke.
"Have you considered my generous offer?" The man nodded.
"You give us supplies and the 'Lava nomad' promises to get rid of the bandits that are plaguing us, we have already accepted your offer."
Kuvira smirked, looking back at Bolin, she knew from there she had won.
"Well, Bolin, are you ready to help these people?"
Bolin didn't know what to do, on the one hand, he couldn't deny the pleading looks of the people of the town but on the other he didn't want to go looking for a fight. Still, he couldn't say no now, not without feeling like he had let all those people down.
"Yeah… Yeah, I'm ready."
After the bandits were beaten
Bolin slammed his hands down on Kuvira's desk as she lifted three other metal pieces and slotted them into their places on a map.
"You used me, you knew I wouldn't say no in front of those people and you used that to get me to do what you wanted."
The woman turned away from the map, facing the seething lava bander, metal was already starting to groan slightly under his feed as it heated up, something that happened wherever he got angry nowadays.
"Yes, I did, but do you know how much support just your presence has garnered us. Three more provinces have agreed to join us now that the news of your joining us has spread, if this keeps up we could have the Earth kingdom stabilised in just 2-3 more years, instead of the decade it probably would have taken. Don't you see Bolin, you rallied these people to accept us, and that was just your name, imagine what your actions will do."
Bolin had to admit, it didn't sound so bad the way she put it, and if he was helping people, then maybe going with her was a good idea.
"Look…um can I have some time to think on this?" Kuvira smiled slightly, finally showing a positive emotion to him.
"Take whatever time you need. But Bolin, I hope you will accept, I need people like you in this army, people who won't lose sight of what we are fighting for. I think this is the path destiny meant for you to take. To help lead the Earth Kingdom to a new tomorrow."
Over the next few weeks, Bolin began helping out, rooting out bandit camps, helping deliver aid to the provinces, and basically being the perfect soldier in the 'Great Uniter's army. Kuvira smirked as she added more and more tiles to her map, over a tenth of the Earth Kingdom had rallied to her cry with Bolin by her side, and she was going to make sure he helped her.
After 6 weeks of being in Kuvira's army Bolin was called into her office at the front of the train. Quietly sliding the door open and close to allow himself entry, Bolin stood in front of Kuvira.
"Uh… you wanted to see me about something?" He asked.
"Yes Bolin. Remember what I told you when I first told you to join us?"
"Uh yeah, you said people would rally to you because of me."
"Not exactly but close enough, now that you are working with us, and have proven your sincerity to our cause, how many more states do you think have allied with us?"
"I don't know like one maybe 2…"
"Try four."
"Ok Fou- what, that's impossibl- I mean, you told me I was popular but 7 states joined up because of me, you have to be kidding me?"
"I am not Bolin, what you have done for this initiative has been invaluable, and now that you have worked with us for a while, have you reconsidered my generous offer?"
"Well, I've thought about it, and… and yeah, I will join you guys. What I'm doing, its helping the people of this nation… and I think this group is doing some real good, more than I used to do by myself."
Kuvira smiled, an actual smile. Pacing forward and placing her hand on the younger man's shoulder she spoke with surprising softness.
"Thank you Bolin, I really do appreciate what you are doing here. I know that together, all of us can make this nation a safer and better place for everyone."
Bolin smiled brightly.
"Well, you can count on me."
And so began Bolin's run with the future Earth Empire.
I hope you enjoyed this story. I wrote off a random idea and turned it into a story. Some other random stuff will undoubtably show up over the course of the week so heads up.