Maybe Simon. If the fanfic takes an alternate path where Clary and Simon end up in a romantic relationship, he could be the father. However, he might be away or unable to be with her when she gives birth.
One possible scenario could be that Clary is in a situation where she has no one around due to some unforeseen circumstances like being stranded in an isolated place. Another could be that she chooses to be alone because she doesn't want others to see her in a vulnerable state during childbirth.
It could be a mysterious and powerful wizard. He might have used his magic to be with Ciel in a way that led to the pregnancy. His powers and knowledge could play an important role in the story, perhaps he has to use his magic to protect Ciel during the pregnancy.
Well, it could be about the challenges Clary faces during childbirth, like her fear and the support she gets from her friends. Maybe her partner is by her side, holding her hand through the pain.
Obviously, Clary herself is the most important character as she's the one giving birth. Her partner would also be crucial, providing support and sharing the joy of the new arrival.
It could be that the father is an unknown wizard who Harry had a brief encounter with. Maybe it was a one - time magical connection that led to the pregnancy.
Puck could be a likely candidate as he had a relationship with Quinn in the Glee series. Their on - again - off - again relationship makes it a plausible scenario for him to be the father in the fanfiction.
It could be an old flame that Sakura had a brief encounter with. Maybe it was a relationship that ended suddenly, and now she's left alone with the pregnancy.
It could be a mortal man who somehow managed to catch Artemis's eye. Maybe he was a great hunter like her, and their brief encounter led to the pregnancy.
The most obvious choice would be Percy Jackson. Given their long - standing relationship in the original series, it makes sense that he would be the father. Their relationship has been through so much, and having a child together would be a new chapter in their story.
There's also the possibility that it's an unknown stallion from a far - off land. Twilight could have had an adventure in a different region and met someone there. This would add an element of mystery to the fanfic, as the readers would be curious to learn more about the father's background and how he and Twilight met.