Unique power combinations. If Naruto has cold - based powers in the DxD universe, how he combines them with the existing abilities of DxD characters is key. For example, if he can freeze the Boosted Gear's power - up process for a short time, that's a really interesting concept.
Character development is key. When a fanfic shows how Naruto and Gabriel grow and change in the combined universe. Maybe Naruto becomes more understanding of the different species in DxD, and Gabriel learns about the ninja way. It also helps if other characters from both series are well - developed, not just the main two. There could be interesting interactions between Sasuke and some of the devils in DxD, for instance.
Highschool DxD America fanfiction often brings in new characters that are unique to the American context. These new characters can add fresh dynamics to the story, whether they are human allies or new types of devils.
The Riser Peerage fanfiction stands out because it can take the often - overlooked aspects of the peerage and make them central. For example, the training and development of the peerage members can be a major focus. We might see how they train together, learn new skills, and bond as a group. Fanfictions can also introduce new challenges for the peerage, like dealing with a curse or a mysterious force that targets them specifically. This creates a sense of exclusivity and uniqueness compared to other parts of the Highschool DxD fanfiction world.
Giving the elf OC a distinct personality trait. Such as being extremely curious about human technology and constantly trying to incorporate it into their elven magic. This would create humorous and interesting situations as they interact with the other characters who are more used to traditional magic and may not understand their fascination with modern gadgets.
Another concept might be an OC with a Stand that has the ability to manipulate time. In the DxD world filled with battles and power struggles, this could be a game - changer. The OC could use it to freeze time during combat, giving them an edge, or to reverse time to undo a harmful spell or attack.
Unique crossovers can make a fanfic stand out. For example, if it combines the magic and devil - related elements of Highschool DxD with the strategic and political aspects of Code Geass in an interesting way. Maybe the main character has to use Geass powers in the Highschool DxD world to deal with devils and fallen angels.
Well, in these fanfictions, the alternate Issei can bring about a whole new set of plotlines. Maybe he has a different attitude towards the devils, angels, and fallen angels. Instead of the usual somewhat lecherous but good - hearted Issei, he could be more serious or more mischievous. This alteration in his personality can lead to different story arcs, such as different battles, different ways of resolving conflicts, and different character growths.
The combination of the High School DxD universe and the Journey King elements makes it stand out. It can bring a fresh perspective to the familiar DxD setting. The Journey King aspect can add a sense of epic adventure and a quest - like storyline that might not be as prominent in the original DxD story.
Unique character design. If the original character (OC) has a distinct personality and backstory that fits well within the Highschool DxD universe, it can make the fanfiction stand out. For example, an OC gamer who has a special power related to gaming that also has an impact on the DxD world in an unexpected way.