It could end with separation. Their differences may be too great to overcome, and they are forced apart. Maybe the forces of heaven and hell won't allow their union.
One way it could end is with the devil turning good. The power of the angel's love is so strong that it transforms the devil completely, and they live happily ever after in a world that accepts their love. Another possibility is a tragic end. For example, they both die trying to protect each other from the wrath of their respective realms.
The ending might be a bittersweet one. They find a way to be together, but they are always in between worlds. They can't fully belong to either heaven or hell. Or, the angel could be corrupted by the devil's influence over time, and they end up causing chaos together, which is a very different and darker kind of ending.
In an 'angel devil love story', the angel, with its golden wings and kind heart, fell in love with the devil who had a dark charm. The devil, though used to a life of chaos, found peace in the angel's presence. However, their love was not easy. The celestial and infernal realms were against it. The angel risked being cast out of heaven, and the devil risked losing his power in hell. But they were determined to fight for their love.
In an angel and devil love story, there could be a lot of obstacles. The angel is supposed to represent all that is good and the devil all that is bad. But love doesn't follow such strict boundaries. Let's say the angel is Gabriel and the devil is Lucifer. Gabriel was sent to redeem Lucifer, but instead, they fell in love. Their love defied the natural order. The other angels were horrified, and the devils were confused. But Gabriel and Lucifer held on to their love. They believed that love could change things, and they hoped that their love could bring a new understanding between the two opposing forces.
For an 'angel x demon love story' to end happily, they might need to prove that their love is strong enough to withstand any challenges. They could do this by saving each other or their respective worlds from a great danger. This would show that their love has a positive impact and could lead to acceptance. Also, if they can combine their powers in a unique way to create a new, harmonious existence, that could result in a happy ending.
One possible ending is that they find a way to be together. Maybe they create their own realm where they can be free to love without the interference of the angelic or devilish worlds. Another ending could be that they are forced apart. The angel is made to forget the devil and returns to heaven, while the devil sinks back into his dark ways. Or perhaps they sacrifice their love for the greater good. The angel stays in heaven to continue its good deeds, and the devil stays in hell to keep the balance, but they always remember each other in their hearts.
One common theme is the struggle between good and evil within the relationship. The devil represents temptation and chaos, while the angel stands for purity and order. Another theme could be redemption, where the devil may be redeemed through the love of the angel.
Another ending could be that they fight against all odds and manage to change the views of both the angelic and demonic realms. They prove that love can exist between the two and are allowed to be together. They then live in a sort of in - between world, a place where good and bad can co - exist in harmony because of their love.
There are also stories where the angel - human love story ends with a new beginning. The love between them might inspire change in the world around them. Maybe it leads to a new understanding between the angelic and human realms. For instance, in a story where the angel's love for a human makes the angels realize the value of human emotions and they start to interact more positively with humans. So, instead of a typical 'happily ever after' or 'tragic' end, it's a more complex and forward - looking ending.
There are also endings where the relationship is just a brief encounter. The human realizes the danger or the wrongness of being with the devil and decides to break it off. The devil, having had this experience of love, might be left to ponder on what could have been, while the human goes on to live a normal life.
For the angel, give it flaws. It doesn't have to be perfect all the time. Maybe it's a bit too prideful in its celestial status. For the devil, show that it has some good in it, like a sense of loyalty to its friends in hell. That makes them more believable.
It has a rather dramatic and unexpected ending. Angel faces a final showdown with a powerful villain and makes a heroic sacrifice.