One possible theme could be motherhood itself. Despite being in a supernatural context, the idea of a mother - figure for angels can explore the universal aspects of nurturing, protection, and the bond between a mother and her children. Another theme could be power and its implications. As the mother of angels, she would likely possess great power, and the fanfiction could examine how she uses it, whether for good or for ill.
In such a fanfiction, the relationship between the mother of angels and other supernatural beings would be an interesting aspect to explore. She could be in conflict with demons, or have a complex relationship with humans. Maybe she is a protector of the angels, guiding them in their celestial duties, or she could be a more mysterious figure, whose true intentions are not immediately clear.
Love and loyalty are also prevalent. Angels can form deep bonds of love and loyalty, whether it's towards other angels, humans, or a cause. For example, an angel might fall in love with a human and have to choose between heaven and that relationship.
One possible theme could be hope. The angels might bring hope to the characters during the Christmas season, which is often associated with new beginnings.
Another theme might be the relationship between Snape and the other characters in the context of being a single mother. For instance, how would the students react? Would they be more empathetic towards him? And also, how would his former enemies or friends, like the Marauders' friends or Dumbledore, interact with him in this new role? There could be a lot of character - development - related themes.
There are several potential themes. For example, the theme of identity. Australians in the 'City of Angels' may struggle to maintain their Australian identity while being influenced by the new environment. Love and relationships could also be a theme. Maybe an Australian falls in love with someone from the 'City of Angels' or has to deal with long - distance relationships. Additionally, the theme of opportunity might be present. The 'City of Angels' could be seen as a place full of opportunities for Australians, whether in terms of career, education or personal growth.
Another theme might be about redemption. If the city is full of crows which could represent sin or chaos, and angels are present, it could be about characters seeking redemption through the influence of the angelic elements in the story. Also, the coexistence of different elements, like how the city manages to have both the crow - like and angel - like aspects within it, could be a theme. It could explore the balance or imbalance between these two very different forces.
If it's a positive fanfiction, possible themes could be the mother - daughter relationship, like how the mother passes on her wisdom to Sakura.
In an 'abused mother gets married' fanfiction, a common theme could be transformation. The mother is likely to transform from a victim of abuse to a more confident and happy person in her new married life. Another theme might be trust. It could explore how she learns to trust again after being betrayed in the abusive relationship. And then there's the theme of new beginnings. The marriage symbolizes a fresh start for her, a chance to break free from the past and create a better future. This could involve her exploring new hobbies, making new friends, and overall having a more positive outlook on life.
One possible theme could be family. Since it involves 'papa', it might center around family values during Christmas with the angels playing a role in bringing the family closer or protecting the family unit.
One possible theme could be the distortion of family relationships. Given it's about a mother's 'dark love', it might explore how love can turn into something abnormal within a family context.