One common theme is the exploration of Lucifer's complex character. In many fanfictions, his fall from grace and his inner turmoil are delved into. Another theme is the power dynamics between Lucifer and other supernatural beings in the 'Supernatural' universe. Often, there are illusions used as plot devices to mislead characters or the reader, adding an element of mystery.
A common theme is the battle between good and evil. In both Supernatural and Lucifer, this is a central concept, and fanfictions often explore it further. For example, how characters are tempted by evil or strive to do good in difficult situations.
Power struggle is a very common theme. The idea of Lucifer being a powerful entity and the use of bondage to either restrict or enhance that power. For example, in many fanfictions, the hero might try to use bondage to limit Lucifer's abilities.
One common theme is redemption. Writers often explore the idea of Lucifer seeking or being offered a chance at redemption through the comfort he receives. Another theme is the struggle between his dark nature and the possibility of change.
Redemption is often explored. In Supernatural, many characters are on a journey of redemption, and when Lucifer is added to the mix, the idea of whether he can be redeemed or not becomes an interesting plot point. For example, some fanfictions show Lucifer being influenced by the Winchesters' sense of justice. Another common theme is the disruption of the natural order. Lucifer's presence in the Supernatural universe throws a wrench into the already complex balance of good and evil, heaven and hell, that exists in the series. This can lead to all sorts of chaos and interesting story developments.
Redemption is also a theme. Some fanfictions might depict the female Lucifer trying to atone for her past wrongs or find a way to be something other than what she was originally created to be. This could involve her interactions with the main characters like Sam and Dean. She might try to help them in their battles against evil as a form of self - redemption. It often makes for an interesting character arc.
One common theme is the clash of powers. Lucifer has his own set of demonic powers and in the Supernatural world, there are various powers like the Winchester brothers' hunting skills and the angels' powers. So, how these powers interact is often explored.
Power struggles are common. Both shows deal with powerful beings, so in the crossovers, there's often a fight for dominance between the characters from each universe.
One common theme is redemption. Since Lucifer is often seen as a villain in Supernatural, many fanfictions explore the idea of him finding redemption through his relationship with his mate. Another theme is power. The combination of Lucifer's power and the role of his mate in relation to that power is often explored.
One common theme is redemption. Often, the presence of a soulmate makes Lucifer question his actions and strive for redemption. Another theme is the power of love. The connection with the soulmate is so strong that it can overpower Lucifer's demonic nature. And also, there's the theme of fate. It shows that even a powerful being like Lucifer is bound by the concept of a soulmate which is pre - determined by fate.
Sam Winchester is quite popular to pair with Lucifer. Their connection in the show, with Sam being one of Lucifer's vessels, makes for an interesting dynamic in fanfiction. Also, Castiel. The angel's moral compass and his power contrast well with Lucifer's nature.