There's so much behind the fact that after the Merge, Arin stands facing Imperium, and Sora sees out her bedroom window which shows us a view of Ninjago. It's as if the visual language is telling us they're fated to meet each other.

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There's so much behind the fact that after the Merge, Arin stands facing Imperium, and Sora sees out her bedroom window which shows us a view of Ninjago. It's as if the visual language is telling us they're fated to meet each other.
Arin's grappling hook represents a sort of "red string of fate" for Sora and Arin, not that it denotes that they're destined to be romantically together, but that it symbolizes their lasting connection, no matter what their relationship status is.
Examples include Arin using his grappling hook to carry Sora:
Sora finding his grappling hook in unexpected places, when Arin isn't with her (even though in the second instance, his grappling hook was only an illusion, yet somehow useful):
Arin and Sora using his grappling hook to save each other:
Even when her and Arin fell out and he went to Ras' team, automatically making him as sort of their "enemy," their bond still remained.
Sora understands Arin so well --- I mean, the whole fandom knows this --- but it's her heart-to-heart with Arin in the World Forest that really sets it in stone.
To set the scene, Sora and the Ninja run into Lord Ras and Arin in the World Forest. This is the first time they've seen Arin since he disappeared with Lord Ras after they held off looking for his parents in favor of the Tournament of Sources, so they are distraught --- some a bit more shaken up than others, but shocked, concerned, and upset nonetheless. Arin tells him this is his choice; he doesn't show any signs of wanting to return.
Soon, Lord Ras, Arin, and the Ninja are in a brawl against one of the Forbidden Five and Rogue Jay, and during the fight, Arin tries to hang onto a tree branch, but his grip slips and he falls. Sora jumps out of the fighter jet she's piloting, pulling out Arin's grappling hook and using it to save him. Now they're hanging from the tree by his grappling hook, having an strained yet intimate moment together.
The first words Sora says to Arin is, "I'm sorry." Throughout Arin's journey with Lord Ras, he felt betrayed. He believed the Ninja neglected his desire to find his parents, and that his best friend thought he wasn't capable enough to perform Object Spinjitzu to save someone's life, which harbored resentment in his heart. To him, no amount of apologies could ever fix what had happened. But in this vulnerable moment, when his walls were down, her words made him feel validated --- that it was not wrong for him to feel the way he's feeling when they played a part in it, despite the circumstances which led him to feel that way being out of their control. Her accountability for herself and on the Ninja's behalf opened the door for the rest of the conversation.
Throughout seasons 1-2, Arin struggled with feeling like he was a part of the Ninja team. He was a normal kid with no Elemental powers and wonky Spinjitzu, and his only saving grace, Object Spinjitzu, was something he hasn't mastered yet. He felt like the odd one out, so being with Lord Ras could give him a sense of belonging while also improving his skills. So when Sora says, "Come back with us," (emphasis on "us") she's creating space for him to be in the team again, to be with the people who actually love and care for him, who he used to love and care for --- and she knows he still does. In the words, "It won't be like before," Sora is telling Arin that they won't make him feel neglected anymore, and in, "We can find your parents," she tells him his greatest desire can be fulfilled, and that they can finally complete the mission him and her were on that was held off because of the Tournament of Sources, the one they had decided to do together.
In 3-4 short sentences, Sora addresses and finds a resolution to what Arin desired in his heart, helping him feel loved and understood in a way no one else did.
part 1 | part 2
Sora and Arin balance out each other. They and their teammates they are usually paired with for missions are essentially the same people, but Sora and Arin compliment each other.
Sora and Wyldfyre are the queens of sass. They know what to say to keep people in check, and they are intelligent in their own ways (tech smart for Sora, street smart for Wyldfyre). Sora and Frak have troubled pasts, being raised in toxic, dysfunctional households, and have created a stubborn personality to cope. That's why it hardly felt like Sora could be herself in season 4 part 1, because she has to deal with people who mirror her. On top of that, she had to be Frak's confidant, and with Wyldfyre and herself worrying about Riyu, she barely had time to process what she felt about the back-to-back events that transpired. We don't really see a glimpse into her mind like we usually do, and that's what made her seem disconnected with everyone else. Sora needs someone who can reassure her and get her to open up --- break her out of her shell of stubbornness and sarcasm. So far, Arin was the one who has created that emotional safe space for her. With Arin, she can truly be herself.
Arin and Euphrasia are sweet and kind, your typical angel-coded characters who are always working to improve their respective skills, which they are occasionally insecure about. They can read each other's minds and have helped each other through comfort, teaming up together, and learning new things from each other. However, their relationship feels too easy, almost predictable. Arin needs someone who can challenge him, not in a competitive way, but character-wise. Yes, Arin and Euphrasia are supportive of one another, but has she or their relationship drove him to improve his character? When he's with Euphrasia, he is only doing what Sora has encouraged him to be --- kind, generous, and hopeful. Sora has created space for and inspires him to grow, seeing how he's gradually mastering Object Spinjitzu, and how he was able to defy Ras when a couple seasons ago, he would probably be too gullible to. Euphrasia is nice (for a lack of a better word), Frak is one of his best friends, and he teamed up with Wyldfyre before, but none of them have achieved the results that Arin sees in himself because of Sora.
Now, I understand if the writers intended for Sora and Arin to be sidelined in order to support the focal characters in season 4 part 1, which are Lloyd and Frak respectively, but that is not the point here. Sora and Arin work well together because they fill-in the gaps where they fall short and turn it into advantage. They could still work independently or with other people, but they are the most effective and powerful with each other. We've seen their teamwork throughout the seasons, especially in season 3 part 2, when they fight Ras together. They even told him that he couldn't win because they had each other.
Additionally, the show explains this itself, but on the surface level: in season 2 episode 3, after they got out of the Phantasm Caves, Sora and Arin realize they have something the other hasn't --- Arin doesn't have Elemental Powers, and Sora didn't know Spinjitzu --- but at the same time, that's what made them a good team.
As I was watching this scene, I realized that Euphrasia doesn't know what Sora and Arin are talking about. She has never been to Imperium before --- besides when she crash-landed outside the city once, but that was during a time of peace.
Frak and Wyldfyre know more than her since they've been there before, especially Wyldfyre, who saw and orchestrated the liberation of Imperium with them. But whereas Wyldfyre was mostly with Kai, Sora and Arin were together when that happened. And the first time they went to Imperium together, which was to destroy the Photacs, Wyldfyre may have already been in the city at that time, but Sora and Arin infiltrated it together. They were in this since the beginning.
This was something they went through, and they turned it into an inside joke only they could understand. There's an intimacy and closeness to that.
Is it a coincidence that Sora and Rontu have same/similar color palletes? Or that Sora was the one struggling with Spinjitzu in Season 2 Part 1 when Rontu was the one who taught it? Or that Sora described herself as a dragon in Season 1 Part 2 when Rontu is a dragon? Or that Sora was the one worried about Arin when he joined Ras when Rontu was worried about Egalt when he contracted Wasting Sickness?
Is it also a coincidence that Arin and Egalt have a sort of dark, rugged look to them, especially with Arin's Season 3 design? Can we mention how Arin's torn black sleeve compliments Egalt's feathers? Can we mention how they both have a heavy aura to them, like they have been through so much more than they say they have? Can we mention how they are both driven by their emotions in some way, like how Egalt got upset at Arin for a small mistake when teaching him the Rising Dragon Technique, and how Arin got upset at himself for that same small mistake?
Is it a coincidence that when Egalt passed away in Season 3 Part 2, Sora and Arin have already forgiven each other in Part 1 and repaired their falling-out from Season 2, as if Egalt and Rontu were passing the torch to them? Is it a coincidence that both pairs represent a Yin-Yang relationship, where one person represents darkness and the other light? Is it a coincidence that both pairs have such a close, intimate bond with each other --- even with knowing Sora and Arin are platonic?
IS IT A COINCIDENCE????
(If I have missed some things, please feel free to reblog and give more reasons that prove this IS DEFINITELY NOT a coincidence. I would like to read your thoughts on this! ✨️)
Sora knew what it was like to be deceived, to be a puppet for somebody she looked up to. She thought Dr. LaRow was making Imperium a better place for every living thing --- humans and dragons --- but that was ultimately crushed, and she was alone when it happened. No support whatsoever, not even from her parents, who you'd expect should be giving her that support.
No wonder she felt so guilty when Arin found out that she successfully tried to make it look like he did Object Spinjitzu when he believed, for the longest time, he was able to do it himself. When they meet again after they fell out, she apologized to him because no one ever apologized for lying to her, and she reaches out to him because no one had comforted her after she escaped from the deception. No wonder she was there for him when he inevitably had to defy to Ras, because perhaps she would've fought Dr. LaRow when she found out, if only she had somebody who stood with her, too. She decided to be there for Arin, because she knew what it was like trying to do the right thing alone, and knew he would need all the support he could get.
The formation of Sora and Arin's unconventional bond was not influenced by their parents (they were absent from their preteen-teenage years) or society (was being repaired because of the Merge). Our parents and society are usually the ones that shape our perception of relationships, but throughout the most character-molding period of Sora and Arin's lives, the typical molders are not there to guide them into how their relationship --- friendship, for that matter --- is supposed to look like, is supposed to be labeled, supposed to be. They were only guided by their deep love for each other, and their past experiences with love. There was no one telling them what their boundaries should be like, how they should be acting with each other, and what to define their relationship with, so they discovered it on their own. That's how Sora and Arin's friendship is so unique.