Darling is used as an affectionate form of address to a beloved person. Angel is a guardian spirit or guiding influence, also a gift sent from heaven.
If someone is a darling-angel to you, you are completely in love with them or they are not your darling angel. You can have many girls but there is only one darling angel for every one person, you may not know it at first but she will be your bestfriend, sex buddy and your most beautiful woman in the world.
dan: she is my darling angel
Oliver: so who would your darling angel be?
russle: She would have brown eyes, olive skin, brown curly hair, skinny, she would have lovely hands. She would be brilliant at art and have a good sence of humor.