歹毒空集少女
[dăi dú kōng jí shăo nǚ]
Literal translation is 'vicious empty-set girl'. The term 'vicious' could imply cunning or mischievous rather than truly evil, and 'empty set' from mathematics means a set containing no elements. So, it portrays a playful, tricky yet pure girl who might act naughty but has no harmful intentions.