While Ninjago is my favorite LEGO line, it has its inconsistencies, plotholes, and overall unexplained stuff. Here's a top 11 list in no particular order! Why top 11? Because I like to copy Nostalgia Critic!
Number 11: Takutanuva Dragon
In 2012 (Not the movie everybody forgot about on December 22, 2012), the Ninja had to get new vehicles, because toy sales will go through the roof! So they had to get rid of the Dragons, at least for 10 episodes. And they did! The reason Sensei gave was that they had to go through Dragon puberty... OK! 10 episodes later, we're met with this 4-headed Takutanuva Dragon, which similarly to Diglet and Magnemite, is what happens when you go through Dragon puberty! You just get more heads! After the season finale, we see it every once in a while in the first half of the "Final Battle" season, but once the Ninja go to the Dark Island, it disappears! Then, it takes Wu, Misako, and Zane's dad to the "Final Battle". In rebooted, it's merely mentioned in episode 27 by Brad, never to be heard from again. Hopefully we can see it again in the future, but only time will tell.
Number 10: Zane
Zane is a robot. He is not a cyborg as some people think, as proved by something he does in episode 34. I don't want to spoil anything, but Zane does something in episode 34 that proves he's a robot. With that in mind, how can he eat? He did leave that note to Kai in episode 2 stating that he ate the last of the Dehli Meat. Also, as proven by the flashbacks in episode 7, he was built looking exactly the same as usual. He's a robot. He doesn't age like humans do! With that in mind, how is it that in episode 18, the episode where the Ninja become kids, he also becomes a kid? I don't even think he understands it, judging by his malfunction in the episode.
Number 9: The Serpentine
So in 2012, LEGO needed new Ninjago villains because toy sales will go through the roof! So they gave us the Serpentine, Chima predecessors that once ruled Ninjago! So, humanity eventually rebelled against the Serpentine and drove them underground into 5 tombs, one per Tribe! Why didn't the humans kill the Serpentine, how were the humans able to overthrow the Serpentine, why were the Serpentine separated, and why were the Anocondrai the only ones to get hungry?
Number 8: Time Travelling Muaka Tried to Prevent This!
You knew I would cover this. It's the episode that gave your migraine a migraine! The first 15 minutes were OK, but the last 5... where do I start? Well, the Golden Weapons merged with the Takutanuva weapon to create... Team Rocket! I guess Team Rocket is blasting of agaaaain! How did that happen?! Tell me. How in Ta Koro did that happen?! Anyways, at the end of the episode, the Ninja are teleported to the Destiny's Bounty (even though the Time Portal was in Outoborous), and Lloyd doesn't know about the Megaweapon. If that is the case, then how did he get big in this Universe? If there was no Mega weapon, then the Grundle was never awakened, and the Grundle is what caused Lloyd to use the aging potion. The Ninja don't even try to get an explanation.
Number 7: Pixane
This is more of an unexplained thing. If P.I.X.A.L. used Zane's design to create the Nindroids, does that mean the Nindroids are P.I.X.A.L. and Zane's children?
Number 6: Scientifically Accurate Ninjago
Spinjizu should, realistically speaking, not only make you incredibly dizzy, but you would be set on fire, electrocuted, pelted in rocks, or frozen.
Number 5: New Ninjago City
How is it that in the span of at least a year, at most 5 years, Ninjago went from apocalypse to futuristic utopia? I mean, you don't see futuristic police mechs in The Last of Us, do you? I know Cyrus Borg is a genius, but for crying out loud, this seems a little too sudden.
Number 4: JayxNya and ColexCake
In the beginning of Rebooted, Nya finds this perfect match console that says she's compatible with Cole. Go home, perfect match console, you're drunk! Everyone knows that JayxNya is second best ship. The first is AlenaxEljay! How on earth (Da dun Tsss) is Cole a better match for Nya? As for Cole, get back to your cake! And then Nya actually buys this Rahi dropping as proof! She is about as indecisive as Bella! At least Ninjago is still a better love story than Twilight.
Number 3: Temple of Light
You know about the Temple of Light, that pathetic excuse for a Ninjago set? Well, in episode 23, when entering the Temple, the Ninja notice that on the wall is a series of pictures showcasing the Ninja's past, present, and future. Instead of doing what any normal human being would do in this situation and pay attention to what it says they will do in the future, they go on and on about what it says they did in the past. Some might say it doesn't say what they do in the future, but it did show them creating the Elemental Blades and KX suits, and these pictures were very likely created thousands upon thousands of years ago, so who's to say it wouldn't say what they'll do in the future?
Number 2: Stone Army
So, after the Serpentine's year was up, the Ninja needed newerer and baderer enemies to fight. So, we got the Stone Army, an army of stones. Need I say more? OK. The Stone Army and General Kozu, or as I like to call him, General Kazoo, were created by the Overlord to fight the First Spinjizu Master. OK. Why? If the First Spinjitzu Master created Ninjago all by himself (not counting the Golden Weapons that he used to create Ninjago), then an army of rocks should be no problem! But wait, here this! The First Spinjitzu Master sealed the evil Onu-Koronans underground, just like the Serpentine! Why? I know this is a kid's show, but they're rocks. Even if they are "indestructible", the Overlord was able to defeat the Stone Army when Dareth controlled them, so if the Overlord and First Spinjitzu Master are on par in terms of power, and the Overlord can defeat the Stone Army, why couldn't the First Spinjitzu Master do so?
Number 1: Lost in Translation
So, when Rebooted premiered, I expected it to be awesome. And while it was awesome, some things were, if you will, lost in translation. These were things that were present in the "Final Battle" but haven't been seen in Rebooted and their reason for not being there lacks explanation. The Ultra Sonic Raider and Ultra Dragon were both mentioned by Brad in episode 27, but other than that, they haven't been seen or heard from since the "Final Battle". The KX suits and elemental blades have seemingly vanished, as the Ninja have not even mentioned them. The elemental blades in particular would prove valuable in the struggle against the Nindroids. While the Ninja don't do the obvious and hack every single Nindroid, I could see them wielding an elemental blade as a primary weapon, and a techno blade as a hacking tool/means of deflecting Nindroid lasers. However, as of the time I am writing this, their previous robes and weapons have not been seen or heard from since the "Final Battle".
So, that was my top 11 Ninjago Plotholes, inconsistencies, and Unexplained Stuff. Make sure to leave a reply if you would like, and goodbye.