Well, in Kingdom Hearts light and darkness fanfiction, the idea of alternate universes where the roles of light and darkness are reversed can be really cool. It makes you see the characters in a whole new light. Also, the concept of a character's inner struggle between light and darkness can be delved into more deeply than in the original games. Fanfiction can show how a character might gradually be consumed by darkness or find new ways to embrace the light.
In this type of fanfiction, the relationship between different worlds in terms of light and darkness is often explored. Some fanfictions might show how a world that was once full of light has fallen into darkness due to certain events. There are also concepts like the discovery of hidden powers related to light and darkness. For instance, a character might find a new way to combine light and darkness to create a more powerful form, which adds a new layer of depth to the story and the lore of Kingdom Hearts.
In Kingdom Hearts Darkness fanfiction, there are often concepts related to the origin of the darkness. Some stories might explore whether the darkness was always there or if it was created by some ancient force. There could also be the idea of a character having to master the darkness instead of simply fighting against it, like using the power of darkness in a controlled way to fight even greater threats in the Kingdom Hearts cosmos.
Some interesting concepts include alternate universes where the characters have different roles or relationships. For example, Sora might be a villain instead of a hero. Another concept could be exploring the backstories of minor characters in more depth, like how they came to be in the different worlds.
One interesting concept could be the exploration of the darker sides of the characters. For example, seeing how Sora might struggle with darker impulses or a corrupted Keyblade. Another could be alternate universes where the Heartless have completely overrun the worlds and the heroes have to fight in much more dire circumstances.
One concept could be Naruto and his friends being Keyblade wielders. They could travel between different worlds in the Kingdom Hearts style, using their ninja abilities along with the power of the Keyblade. For instance, Naruto's Rasengan could be combined with a Keyblade attack. Another idea is that the Akatsuki are like the Organization XIII in Kingdom Hearts, with each member having their own unique powers and goals related to both the Naruto world and the Kingdom Hearts concepts of hearts and darkness.
One interesting concept could be a new original character (OC) with a unique Keyblade design. For example, an OC whose Keyblade is shaped like a musical instrument, representing their love for music and how it ties into the power of the Keyblade. This could add a fresh dynamic to the battles and interactions in the Kingdom Hearts 3 universe.
Sora is often very popular. He is the main character in the original games, and in fanfiction, his journey with light and darkness can be further expanded. Kairi is also popular, especially when it comes to her role in the balance of light, and how she might develop new powers related to it. Riku is another favorite as his struggle with darkness in the original games makes him a prime candidate for in - depth exploration in fanfiction regarding light and darkness.
One idea could be creating an OC who is a keyblade wielder from a forgotten world consumed by darkness. This OC could be on a journey to find a way to restore their world while also struggling with the allure of the darkness within them.
What makes it interesting is the potential for deep exploration of the Kingdom Hearts concepts. The Darkness can be shown as a seductive force that lures characters in different ways. 'Nothing' can be explored as a state of non - existence that challenges the characters' very understanding of reality. And the war can be a backdrop for exploring themes like sacrifice, loyalty, and redemption. It can also introduce new plotlines and relationships that add new layers to the already rich Kingdom Hearts universe.
One interesting concept could be the fusion of the Kingdom Hearts' unique magic system with the colorful world of Equestria Girls. For example, keyblades might have new forms inspired by Equestrian elements like ponies or the magic of friendship. Another concept could be the crossovers of characters. Characters from Kingdom Hearts might interact with the Equestria Girls in unexpected ways, leading to new friendships or rivalries. Also, the exploration of different worlds within this fanfiction can be exciting. Worlds could combine features from both franchises, creating a whole new and immersive experience for the readers.
One interesting concept could be the unique character designs of the self - inserted original characters (OCs). They often bring fresh perspectives and abilities into the 'Kingdom Hearts' universe. For example, an OC might have a special power related to the Keyblades that we haven't seen in the original game series. Another concept could be the new storylines that are created around these OCs. They can interact with the existing characters in unexpected ways, like befriending Sora or Riku and going on adventures with them that deviate from the main game plot.