The concept of Danny's ghostly abilities meshing with the magic of the Fate universe is really interesting. His powers, like intangibility and flight, could give him an edge in battles against Servants. For example, he could use his intangibility to avoid attacks that would normally be deadly.
Another interesting concept is the idea of Danny being a wildcard in the Holy Grail War. Since he's not from the normal Fate universe, he could disrupt the usual order of things. He might not be interested in the Grail itself but gets dragged into the conflict because of his sense of justice or because he's mistaken for someone else who should be in the war. This could lead to all kinds of plot twists and new alliances forming.
One more fascinating concept is how the characters from Danny Phantom would view the complex moral and ethical codes in Fate Stay Night. Danny, who is used to fighting ghosts in his own world, might find the idea of Servants and Masters and the sacrifices involved in the Grail War very strange. This difference in worldviews could create a lot of internal and external conflict within the fanfiction, which is always engaging to read.
One interesting concept could be the crossover of the power systems. For example, how would a Quincy from 'Bleach' fare against a Servant's Noble Phantasm in 'Fate Stay Night'. Another concept might be the character interactions. Picture Ichigo from 'Bleach' having a conversation with Shirou from 'Fate Stay Night' about their respective ideals of justice and protecting others. Also, the different magical and spiritual realms in both universes could merge in unique ways in the fanfiction, like the Soul Society and the Throne of Heroes interacting in some unforeseen manner.
You could also check out fanfiction.net, though the selection might be a bit more limited compared to AO3. Look for stories that have a high number of reviews and favorites as these are often indicators of well - written and engaging fanfictions. Some fanfictions might take a more comical approach, like Danny accidentally getting summoned as a Servant, which could lead to all sorts of hilarious misunderstandings and adventures.
One interesting concept could be exploring Danny's dual identity in unique ways. For example, how he manages to keep his two lives separate in different scenarios that the fanfiction creates. Maybe in a situation where his ghostly powers start to affect his human life in unexpected ways, like his Phantom side accidentally showing up during a school event.
In this fanfiction, an interesting aspect could be the new ways of summoning Servants. Instead of the traditional methods, the gamer aspect might introduce a system where Servants are summoned based on in - game achievements or levels. This could bring in Servants that are not typically seen in the original story, creating fresh and unexpected interactions.
Another aspect is the exploration of different endings. Fanfiction can take the Fate Stay Night system and create new storylines that lead to unique conclusions. Maybe a scenario where the Holy Grail War has a completely different outcome, like all the Servants teaming up against a new, unexpected threat.
One interesting concept could be the crossover of character abilities. For example, how a Fate Stay Night character might adapt to the world of RWBY and use their magic in a combat system dominated by Dust and Semblances. Another concept might be the exploration of different character relationships. Characters from both universes could form unique friendships or rivalries that are not present in their original stories.
One interesting concept could be unique interpretations of the Holy Grail War. For example, an OC might have a special ability that changes the dynamics of the war completely. Another could be new relationships between OCs and the existing characters from the Fate Stay Night universe. Maybe an OC forms an unexpected alliance with a Servant, which leads to a whole new storyline.
In such fanfiction, a common concept is the OC's role in the Holy Grail War. An OC with godlike abilities might change the very nature of the war. For example, if the OC has the power to nullify all magic for a short period, it would turn the tide of battles completely. Additionally, the moral and ethical dilemmas faced by the OC can be explored. Since they have such great power, they might struggle with using it for good or being tempted by darker motives. Moreover, the design of the OC, both in terms of appearance and personality, is an important aspect. A well - designed OC with a distinct personality can add a whole new dimension to the Fate Stay Night story.
One interesting concept could be how the original Fate Stay Night mechanics interact with the gamer OC. For example, the OC might have unique abilities that change the way the Holy Grail War is fought. Maybe they can level up in a way similar to a game, which gives them an edge over traditional Servants and Masters.
Some interesting concepts in highschool dxd fanfiction include new forms of peerage systems. For instance, a fanfic could introduce a modified version where there are more diverse types of members. In fate stay night fanfiction, the concept of the Grail War taking place in a different setting, like a modern - day metropolis other than Fuyuki, is fascinating. In the context of fanfiction that combines both, a concept could be the use of Highschool DxD's magic system in the Fate universe, or vice versa, which could lead to really unexpected and exciting story developments.