Angel is a rather particular demon. Unlike his peers and family, he is capable of feeling attachment and empathy for others.
As a child, he learned the art of healing from a very wise demon. Angel felt good helping heal the demons wounded from battles. One night, in the middle of the war between angels and demons, he found a beautiful angel very injured, he wanted to help her, but he knew that the demons would kill her as soon as they saw her, so he took her to a distant cave, and there he made several remedies homemade. He stayed with her for several weeks until she felt better, in the process he got to know her a lot, she was not like other angels. They became good friends and started seeing each other secretly.
He knew he shouldn't, but he couldn't help falling in love with her.