Aria Blaze is a character from My Little Pony Equestria Girls and is a major reoccurring character in The Knights of the Multiverse. She's a member of The Dazzlings, and appears in Season 3 as part of the Guild of the Multiverse to get revenge on Sunset Shimmer.
Aria seems to be the more level-headed and indignant member of the Dazzlings; she's rude, sarcastic, speaks in a rather bored disposition, and has absolutely no respect towards anyone. Like Adagio, she is somewhat sadistic, and can be as cold and manipulative as her, even if she doesn't like to admit it.
Aria grudgingly follows Adagio's lead and is not afraid to question Adagio's judgement and plans, and also displays a contempt at being second fiddle to her.
Aria frequently butts heads with Sonata, often calling her "the worst" and arguing with her over trivial matters. (Sisters, am I right?)