Demons or Dark Angels are dark and mysterious creatures.

They once were humans who died in unknown and dark circumstances due to some bad people they knew or got involve with. They all have their own past and reasons.

However, demons aren't the worst people. Demons are people who could still have some hope in becoming good people but have given up.

The Angels messenger went to them after their death and lead them to God where they recieved their powers before being sent to Hell.

Demons have only one power which is based on their past human default or dislike. But Demons also have a weakness which is based on something good that happened when they were human or simply something they liked.

Demons can't breed with other Demons. Relationships between Demons are highly disapproved by God and very rare. However, God decided that love shouldn't be stopped if it is pure and sincere even for Hell's people. That's why he charged the Angels messenger to be the judge in those case. When two Demons fall in love with each other, they have to ask to talk to the Angels messenger who will hear the feelings of both Demons and decide wether those feelings are sincere.

The only mission of the Dark Angels/Demons is to make up for all the bad things they did in the past. To complete this mission, they have to help 100 differents human with important things, like family or mentality. For that they have to get close to them. The more they get close to complete their mission, the more their wings grow. When their mission is completed their black wings will take them to meet God who will decide if they can or not become an Angel.

Demons are alike of Angels when it comes to love and soulmates. There's only one person who's the good one. After mating, the Demons weakness disappears.

Angels and Demons never met before. Demons dislike Angels because they have what Demons have to work so hard to get which is being forgiven for the past and becoming an Angel. Which means that nobody knows what Angel/Demon couples would be like...

Demons can come and go freely in the human world but are absolutely forbidden to enter Heaven.