Diaspro is a naughty, wicked and spoiled fairy, who is not used to being told "no". Because of her higher social status, she tends to mistreat those who are below her. This is seen when she calls Bloom a "peasant" in the first season and when she shouts at one of her servants in the third season. She is also very haughty, and extremely proud of herself.
Diaspro only acts affectionate toward Sky, her ex-fiancé, though it is uncertain as to if she has actual feelings for him, or if it has to do with the fact Sky is next in line for the throne of Eraklyon. She is seen to be most willing to do anything in order to get what she wants, even if what she is doing is against all morality a fairy should consider. During the Tritannus's threat, she tried so hard to get between Bloom and Sky that she did not care about the fate of Magical Dimension and she even opposed Bloom's opinion on forming an union between worlds to save them. She sunk even lower in season 6 where she actually allies herself with the Trix since it meant taking Bloom down in the process, she is also shown to be rather cunning and manipulative, and does not like hard work.