Redemption is often seen. The demon may be seeking redemption through the love of the angel or vice versa. Also, the idea of defying fate or the order of things. Since angels and demons are supposed to be on opposing sides, their relationship goes against the natural order in their fictional universes.
The theme of sacrifice is also quite common. Whether it's the angel sacrificing his place in heaven or the demon sacrificing his power for their relationship. And there's always the overarching theme of love conquering all. Despite the differences, the love between the angel and the demon is strong enough to overcome the obstacles of their opposing natures and the hostility from their own kind.
One common theme is forbidden love. Since demons and angels are often seen as polar opposites in the lore, their relationship is considered taboo.
One common theme is forbidden love. Since angels are often seen as good and demons as bad, their relationship goes against the natural order, making it forbidden. Another theme is redemption. Sometimes the demon is redeemed through the love of the angel.
A prevalent theme is the exploration of identity. The angel may question its own purity when in love with a demon, and vice versa for the demon. The lemon parts of the story add a layer of physical and emotional exploration, which ties into this theme of identity. In many of these fanfictions, the relationship is not just about physical attraction but also about how they redefine themselves through their love.
One common theme is the struggle between good and evil within the relationship. The angel represents all that is good and pure, while the demon stands for the opposite. Another theme could be redemption. Maybe the demon is redeemed through the love of the angel. Also, there's often the theme of forbidden love as angels and demons are from two very different worlds and are not supposed to be together.
One common theme is the clash of personalities. Alastor is very different from Angel Dust, and this often leads to interesting dynamics in the fics. Another theme is the idea of redemption or change, where they might influence each other to become better or worse.
One common theme is the exploration of their contrasting personalities. Angel Dust is often flamboyant and has a seedy past, while Vaggie is more serious and protective. Their relationship can be a source of tension and growth in many fanfics.
Often, in 'angel x spike yaoi fanfic', themes of redemption and self - discovery can be found. Since both characters have their own dark pasts, the fanfics might explore how their relationship helps them to come to terms with their pasts and grow as individuals. Also, themes of forbidden love are quite common as their relationship in the original context might not be so straightforwardly romantic, and yaoi takes it in a male - male romantic direction which can be seen as 'forbidden' in the original setting.
Love is also a frequent theme. There can be love stories between angels and humans or even between angels and demons in some cases. For example, in some novels, a demon may fall in love with an angel, which challenges the traditional view of their relationship and adds an interesting dynamic to the story. This love often has to overcome many obstacles due to their different natures.
One common theme is the struggle between good and evil. Since demons are often seen as evil in traditional views, the fanfic might explore how a human can influence a demon towards good or vice versa. Another theme is forbidden love. Society in these stories usually doesn't approve of a human - demon relationship.