She is voiced by Emi Shinohara in the Japanese version of the anime, and by Wendee Lee in the English version of the anime.
Angel is a young-looking woman of average height with black eyes and blonde hair. It is later revealed that it is revealed that she has two long scars on her back, giving the impression that she once had wings; hence her name.
Angel is a highly enigmatic woman; she rarely, if ever, reveals anything personal about herself, to the point that the majority of information Roger discovers about her is due to being in the right place at the right time. She is often manipulative, using multiple aliases over the course of the course of her work, such as Cassey Jenkins and Patricia Lovejoy. This results in her being highly untrustworthy, particularly by Dorothy; when she claims that she can be trusted, Roger insists that she shows him proof, which she can't provide.
Angel is also quite flirtatious, frequently talking smooth to Roger. Notably, however, he is the only person she acts towards this way, and is usually quite cold towards anyone else, particularly Dorothy, even trying to deny that she hates her when she clearly does. Ultimately, she seems to develop feelings for Roger, and begins to alternate between helping him and the Union.
Despite being a secret agent, Angel is fairly prone to panicking in the first season of the anime, and so often has to be saved by Roger. She's much more competent in the second season, and far more cool and composed during combat. Unlike Roger, she has no problem with using guns, and even tells Roger that he needs to get over his 'no gun' policy. Roger describes her as someone who's always looking for trouble, and says that that's something they have in common.
After being rejected by Roger and realising that he's in love with Dorothy, combined with beginning to regain her lost memories, Angel becomes very bitter and depressed, showing no signs of the aloof, flirtatious personality she showed early in the series. When she comes to Roger's mansion to give him a message and learns he's not there, Angel states that that's just her luck and asks Dorothy to pass the message on to Roger for her, which considering she hates Dorothy, suggests that she has become very desperate. She seems to have a very low opinion of herself, telling Vera, her mother and superior in the Union, that if there is such a place as Heaven, she doesn't deserve to be there.