One common theme could be the power dynamic between them. Since Airachnid is a rather menacing character and Jack is a human, exploring how they interact in terms of power is often seen. For example, how Jack might overcome Airachnid's threats.
In 'jack x airachnid fanfiction', a prevalent theme is often survival. They are in a world full of danger, and their relationship can be centered around how they help each other survive. Jack might use his human wits and Airachnid her Transformer abilities. Also, the theme of discovery can be there. Jack discovers more about the Transformer world through Airachnid, and she in turn discovers new things about humans and their emotions.
One common theme could be the 'forbidden love' aspect, as they are from different sides (Airachnid being a Decepticon and Jack being a human). Another might be the idea of redemption for Airachnid through her relationship with Jack.
One common theme is the battle between good and evil, with Arcee and Jack representing the good side and Airachnid as the villain. Another theme is friendship, like the strong bond between Arcee and Jack that is put to the test by Airachnid's actions.
Another theme is the exploration of an unlikely friendship or more. Given that they are on opposite sides in the original series, fanfiction often delves into how they could bridge that gap. It could involve them having to rely on each other in a dangerous situation in a way that changes their relationship dynamics.
One possible theme could be the challenges they face as a couple with an unexpected pregnancy. It might involve how they deal with the reactions of others in their respective worlds.
Fanfics often take existing characters and put them in new situations. In the case of 'airachnid x jack fanfic', it could be set in an alternate universe where the normal rules of the original story don't apply. It could be a story full of action, with Airachnid and Jack fighting side by side against a common enemy. Or it could be a more character - driven piece, exploring their feelings, motives, and how they view the world around them.
There's also the challenge of making the story engaging. Since it's a fanfiction, it has to stand out from the many other stories out there. You need to come up with unique plot twists and a good pacing. Maybe start with a hook like Airachnid making an unexpected offer to Jack in the middle of a battle. Then build the story from there, making sure to keep the reader interested at every step.
A third common theme could be the idea of redemption or lack thereof. Given their often - cruel and violent natures, some fanfictions might explore if they are capable of any form of redemption. Or perhaps they are so far gone into their dark ways that there is no hope for them. These themes add depth to the fanfictions and make them more than just simple stories about two spooky characters. They can also touch on themes of morality in a very unique and often disturbing way, as the Creepypasta world has its own set of 'rules' when it comes to right and wrong.
One common theme is the exploration of their dark natures. Since both characters are from the horror genre, fanfictions often dig deep into how their 'evil' sides interact. For example, they might show how their methods of causing fear or harm are different yet similar in some ways.
One common theme is friendship. Their relationship often starts as a simple acquaintance and develops into a deep and meaningful friendship. They support each other through various difficulties.
A frequent theme is the exploration of their powers in relation to each other. How do Jack's skills and Ashi's abilities interact? This can lead to some really interesting storylines. Also, the theme of redemption might be present, especially for Ashi, as she might have a past she wants to make up for, and Jack can be part of that journey.