What are some interesting ideas for a Diabolik Lovers male OC fanfiction?

One idea could be a crossover with Vampire Knight. The Diabolik Lovers vampires could interact with the ones from Vampire Knight in a school setting. There could be rivalries over territory or a common prey. Another idea is a crossover with Black Butler. Sebastian could be hired to deal with the unruly Diabolik Lovers vampires, creating a lot of tense and interesting scenarios. A third idea might be a crossover with Ouran High School Host Club. The vampires could accidentally end up at the host club and chaos would ensue as they interact with the flamboyant hosts.

A friendship - centered fanfiction would be cool. Maybe a new character befriends the vampires not out of fear but because they see the good in them. This character could slowly break down the walls the vampires have built around themselves and change their relationships with each other.

One idea could be a crossover where Naruto characters end up in the Diabolik Lovers universe. Maybe Naruto's positive attitude starts to influence the dark and brooding vampires in Diabolik Lovers, leading to some unexpected friendships. Another plot could be a Diabolik Lovers character being sent to the Naruto world and having to adapt to a completely different environment with ninjas and chakra.

One idea could be that the female OC is a new student at the school. She has a special power that she doesn't fully understand yet. Yui befriends her, and together they try to figure out the secrets of the Sakamaki brothers. The OC's power might attract the brothers' attention in different ways, some being more menacing and some being more curious.

One idea could be a crossover where the magic from the Harry Potter world is introduced to the vampires in Diabolik Lovers. For example, a Hogwarts student could accidentally end up in the Diabolik Lovers' world and use spells to both defend themselves from the vampires' advances and also try to find a way back home.

A plot idea could be that Yui gets sick with a strange illness that only Shu can cure because of his unique vampire abilities. This forces Shu to confront his feelings for Yui as he tries to save her. Or perhaps they find an ancient prophecy that involves them and they must journey together to fulfill it, facing many obstacles along the way and growing closer as a result.

One idea could be that Elsa's ice powers attract the attention of the vampires in Diabolik Lovers. Maybe they see her as a unique being and try to either control her powers or use her for their own dark purposes. For example, one of the vampire brothers might think that her ice could be used to create a new kind of weapon or to enhance their lair's defenses.

One idea could be a story where Kou and Yui go on a journey to discover Yui's past. Maybe they find an old diary that holds secrets about her family and how she ended up in the vampire world. This could lead to a series of adventures and a deeper bond between them.

Love and attraction are also prevalent themes. The OC usually forms some sort of romantic or at least a strong emotional connection with one or more of the vampire characters. This can range from a forbidden love story to a more complex relationship where the OC is trying to understand the vampires' true nature while being drawn to them.

A plot idea might involve a situation where the kiss is witnessed by one of the other brothers. This could lead to jealousy and conflict among them. For example, if Laito sees the kiss, he might try to drive a wedge between Ayato and Yui out of his own twisted sense of fun and envy. Or perhaps the kiss unlocks some hidden memories for Yui that are related to her past and her connection to the Sakamaki family.