One common theme is friendship evolving into something more. Since they start with a pre - existing relationship in the game's lore, fanfics often explore how that relationship can deepen into a romantic one.
One great 'noct x iris fanfic' is 'The Bond Beyond Worlds'. It beautifully portrays their relationship with a lot of emotional depth. The author does an amazing job of creating scenarios where Noct and Iris interact in a way that feels both true to their characters and also very engaging.
The exploration of her powers is also a common theme. Fanfics often go into detail about how she can create rainbows, use them as portals, and how she manages the Rainbow Bridge. Some fanfics even give her new powers or expand on her existing ones in creative ways, like being able to use the colors of the rainbow to heal or to create illusions.
One common theme is the balance between work and personal life. Since they are at work, they have to deal with tasks and deadlines, but also their growing feelings for each other. Another theme is cooperation. They often have to work together on projects, and how they collaborate is a big part of these fics.
One common theme is growth. They both grow as Pokemon trainers. For example, in many fanfictions, Iris becomes more confident in her skills and Ash learns new battle strategies from her. Another theme is friendship. Their bond is often explored, like how they support each other through tough times.
A common theme is friendship. Since Naruto is all about bonds and friendship, when Iris is introduced, their relationship often revolves around forming a strong friendship. They support each other through different trials.
Love is a very common theme. Their relationship is at the core of many fanfictions. Another common theme is adventure. Since Barry is The Flash, fanfictions often include them going on adventures together. For example, fighting new villains or exploring new dimensions.
One common theme could be the emotional turmoil that Iris goes through. Maybe she's facing a difficult situation like betrayal or loss in the context of the Loirock universe.
Another theme is growth. Both Ash and Iris grow as trainers and as individuals within these fanfictions. They learn from their experiences in the harem, like dealing with jealousy or competition among the harem members in a healthy way.
Often, the theme of love and commitment is emphasized. Their relationship grows stronger as they face the new chapter of having a child. Also, there can be themes of sacrifice, as they might have to give up certain things for the baby.
One common theme could be the anticipation and excitement of starting a family. It might explore how Ash and Iris prepare for the new addition to their lives, like getting a nursery ready or choosing baby names.