Basically the title! This au will be about the ninjas kids and their adventures with their Master Lloyd. I know it's just a ton of text blocks, let me be. Here's the rundown:

Years after the ninja retire, their children all band together to convince their parents and Master Lloyd to let them train as ninja. Naturally, they agree.

(Oh, and before i forget, this does NOT take place in the same universe as dragons rising as this was originally made before it came out!)

Up first, is Maro Smith, the master of fire. He lived in the monastery for as long as he can remember with Lloyd, as Kai and Skylor dropped him off there know they might not make it out to go protect an invaded village.
Ray and Maya have already died due to old age by now, so he never stayed with them. He's collected, Clever, serious, and extremely interested in becoming the next Master of Ninjago's monastery. He does crack a joke every once in a while, though they aren't the best.
He primarily uses a sword, but doesn't mind using a bow and arrow once in a while.
He excels at spinjitsu and fighting, but stuggles to control his elemental power.
He is 15 years old.

Next, the eldest of the five, the twins, Lynx and Lyra Walker. Lynx is the master of water and Lyra, the master of electricity.
Lynx is the epitome of a theater kid. He's loud, Oblivious, confident, and all around a big personality. Amazing on stage too!
His mom and dad were suprised to see he controlled water, not electricity, as his sister was more close to what someone who controlled water was like, a lot more "go with the flow".
He uses nun chucks like his dad, and was given his first pair by Jay!
Lynx is a pretty well rounded ninja, unless you count the stealth part of ninja-ing.

Lyra is the complete opposite of her brother, she's shy and doesn't like being the center of attention. She's even been said to have a "resting B— face", but once you meet her she's a very nice and honest person! If her brothers the lead actor in a play, she's working lights out back.
Again, like her twin, her parents were suprised to see she had lightning, but it worked out.
Lyra's amazing at spinjitzu and diving her way out of a fight, but when it comes to being direct...well she's trying.
Lynx and Lyra are both 17 1/2(Lynx loves to make that distinction to sound older.)

Cody Julien is the master of ice and your friendly neighborhood nindroid. He's very literal and upfront, doesn't get social cues that often, and loves to play music.
His parents spoil him in the best way possible, but he's pretty humble about it, never really wanting to be the center of it all. He's different from other Droids as he has multiple forms for each stage of life up till now. Zane and pixal made sure that he would function like a kid, but also know what he was.
He mainly uses 2 katanas and is 16 years old.

Then there's the youngest(and my personal favorite) Sierra brookstone. She's the master of earth and is bold, outgoing, and is the life of the party. She has emotional outbursts leading in unintentional earthquakes, but they're very occasional.
Her powers differ from her dad as she isn't super "super-strength" focused.
Her hands don't glow under normal circumstances, but when she extorts enough force and power with her element, they start glowing.  She also uses her powers a lot like earthbending, with stoning and tapping and punching the ground. She can use them like her dad, but finds it more unnatural.
She uses a hammer, or anything she can hit the ground with and excels at her element more than anything(maro's a bit jealous of her since he struggles with the idea that someone younger and less trained than him surpasses him in her element.)
She's only 13.

Now, what happened to the ninja?
(This is taken with premission from Traffic-Light-Eyes on tumblr)

Cole went to art school, even if he was older than most. He went to art school and became one of the best goddamned artists there are out there. He traveled with Pixal and Zane for a hot sec and made it a point to paint from atop every single mountaintop they reached. His artwork is displayed in many museums. One time, a little kid walked up to him and asked him to teach her how to be a good artist. So, he did. After asking her parents, of course (they were very, very starstruck when their daughter came home one day with Cole Brookstone, the famous artist, the black ninja, one of the saviors of ninjago). She became like a daughter to him, and was even allowed to travel places with him. She became a wonderful artist under his tutelage, and gained a lot of recognition for just training under him. He realized he had a passion for teaching, and his young student (with a lot of persistence) got him to start his own little art school. He made sure not to broadcast his name or face on the building, because he didn't want people to come just because he was who he was. It became very successful and a lot of people have a superstition that being in Cole's presence gives you the ability to draw/paint. This is only mildly true (due to his insane ability to teach), but the Ninja make sure tease him about it. (Kai joined a class one day just for fun and was surprised when he ended up leaving the building with a beautiful, realistic portrait of Skylor. They hung it on their wall and they're still baffled on how it happened.) later on, the young girl left to start her own painting career and Cole went to Shintaro to start a family with Vania, who had been long distance with him for a good while. Vania ended up dying from an Illness close to his daughter's birth. His daughter was named after the same young girl who asked to be taught how to be an artist.

Jay and Nya get married immediately. Their celebration of being done with evil was their happy, happy marriage. Everyone was overjoyed with them, and you could even see a misty-eyed Kai if you looked hard enough (it's just allergies, guys, I'm not crying. It's allergies. It's the pollen, I swear). After that, he started working on tech again with Nya. He loves it, but he started to get burnt out. He remembers his time on stage, being the center of attention in both real life and in Prime Empire. He makes a gameshow. It was something silly, at first. Like a "how well do you know the ninja" trivia game. It was super fun and he kept getting asked by producers and directors to host more and more gameshows. He became the Steve Harvey of Ninjago; everyone knew him, everyone watched him. When he openly stated that he was starting to get bored of the trivia-types of stuff, he was asked to act in movies and to host in wipe-out shows because of his expertise in agility. Eventually, when he and Nya decided it was time to have kids, he became the best stay-at-home dad anyone could ask for. He loved it. Sure, he got antsy because of the inactivity, but be quickly cured that by just playing with the kids. They ended up being incredibly sporty because of this.

(This one goes father down the timeline than just the next gen au)
Lloyd kept training the new Elemental Masters, as he felt it was his duty. He really wanted to be like his uncle and train the next generation to make sure they were good people. He didn't expect his deciples to fight off anything major because his team defeated it, but he still wanted them to know how to fight/good vs bad just in case something terrible happens after he and the rest of the ninja weren't around to help. (With his first few students, he was suprised to see the absolute size of threats the new villains made.) His students became wonderful and helpful individuals, which is far more than he could ever ask for. Aside from training, he started studying and researching. He didn't end up dating anyone, not for lack of desire. He just felt in his bones that he would live a long, long life and didn't want to hurt himself by falling in love. He envies Zane and Pixal a bit because of this, but he'd never say that. (they know. They feel terrible but can't do anything about it). They visit a lot, especially after the other ninja pass on. He trains many generations of ninjas and sometimes even uncovers a new way to use the elemental powers or spinjitzu. With each new generation, his students get stronger. He lives a happy, fulfilled life.

Zane left together with Pixal to explore the world. They went place to place, experiencing everything together. They did not marry - not for lack of love, but because they felt their love was so much more to them than some silly social construct. I mean, they are going to live forever, as long as they have the proper maintenance. So, they don't think that they need to marry. Even while traveling, they always make sure to come back for everyone's birthday and for holidays. They bring gifts and recipes and knowledge with them. Once they felt they experienced it all, they returned to Ninjago City and worked with Nya. Well, they didn't really work for her. They just popped up one day, and Nya saw them building in her lab. She let them, and they ended up making an awesome hologram for entertainment. They didn't sell it, but every one in a while, the ninja cuddled up again and watched an almost life-like rendition of a Fritz donnegan movie. Pixal and Zane also decided that they wanted children, eventually. So, they made them. They put parts of themselves into the child and even mixed up their own technical make-up to make their kid: Cody. The two realized that between their adventures they needed a place to stay, so they started on trying to build a home. While pixal was a City Girl, Zane loved the snowy forest of his creation place. They compromised with a canon in the woods and a main place in the city near Nya's lab.

Kai might try to become a martial arts teacher again, but he would eventually become less enthusiastic about it due to the many, many kids he had to deal with. Then, he tried to pick up blacksmithing again. He created a nice little shop back in Ignacia, looking almost exactly like his parents'. Years down the line, the ninja + Pixal, Skylor, etc. have a get-together/reunion. Kai and Skylor reignite their spark, and they try long-distance. It got stressful, so Kai decided to drop everything and move near Skylor. He worked odd-jobs and lived in a glorified shack just to be able to go out with her. Skylor offered him a job at the noodle house, and he accepted. Sadly, the noodle house closed down due to a lack of workers - even though Skylor, Kai, and maybe 2 other people put their all into it. It was sad at first, but they decided to make the most of it. Together, they wanted to create a new restaurant - a mixture of Chen's noodles and Kai's family heritage & recipes. They just couldn't figure out the name. What could incorporate both Skylor Chen and Kai Smith? Kai quickly came up with the perfect solution. On a beautiful night out, while Kai walked Skylor back home after a dinner date, they stopped on a bridge to look at the night sky. Kai got down on one knee and proposed to the love of his life. They married and could finally start their restaurant - The Smiths'. It was a hit, and they lived happily every day happily. They decided that they wanted a kid, but when the small town they lived in got attacked by a gang, they went to save it, leaving their youngest son Maro with Lloyd. He tried to find his older daughter in the fighting, but she was taken. If only that little girl realized how he had looked for her.

Nya would go into techs. Maybe she'd intern or shadow Borg tech, and she'd work there. That's a possibility, but after she learned all she could, she would definitely make her own tech company. She'd be less phone and game tech and more automobile innovations. Maybe she created a new, super-speedy express train. I wouldn't put it past her to invent something akin to teleportation, somehow. That might be far, far into her future. Seeing as her job mostly consists of things that can not touch water, she'd most likely spend some of her time near creeks or waterfalls, just meditating and connecting with her element. Eventually, she might get bored of that and make her tech completely water resistant. Everything.