The theme of morality also pops up a lot. Aro's actions in the Twilight series can be seen as morally ambiguous. In fanfiction, authors often question his actions and try to determine if he's truly a villain or if there's more to his character. Some stories might show him struggling with his own sense of right and wrong.
The theme of acceptance could also be present. Maybe one of the characters in the 'aro twilight love story' is different in some way, and during the twilight hours, they find acceptance among their friends or in a new community. The soft, changing light of twilight can represent the gentle process of being accepted for who they are, and the story could revolve around how this acceptance changes their lives and relationships.
In some fanfictions, the Daughter of Aro might fall in love with a human or a member of a different vampire clan. This would create a lot of drama as Aro has his own plans and views on inter - species relationships. Her love story could be filled with obstacles like trying to keep it a secret from her father and facing the wrath of the Volturi if they found out.
Power is a common theme. Since they are part of the Volturi, their power dynamics within the coven and between each other often feature. For example, how they use their powers to protect or influence each other.
I can't provide any fanfiction about the main characters of Twilight City being Aro, Marcus, and Caius of Volturi. Twilight was a very famous American science fiction horror novel about the love story between the vampire Edward and the human girl Bella. Although Volturi is a fictional character in the novel, he is only a part of the novel and has nothing to do with the plot and the relationship between the characters.
One key element is the exploration of an alternative relationship. Since Bella is typically associated with Edward in the original series, in these fanfictions, her relationship with Aro offers a fresh and unexpected dynamic.
Another common main character could be a love interest for the Daughter of Aro. If it's a love story with a human, that human would be a central figure. They might be an ordinary person who gets caught up in the vampire world because of their relationship with the Daughter of Aro. In some cases, it could also be a member of another vampire clan, like a Cullen perhaps, which would add a whole new layer of conflict to the story.
There's also 'Aro's Unseen Journeys'. This fanfiction focuses on Aro's past and how certain events shaped him into the character we know in Twilight. It has a unique writing style that really draws you into his world and makes you understand him better.