Both dramas have a woman out to get her daughter back from her shady ex, and teaming up with women that were originally her enemy in order to do so. Additionally, they both just have a lot of morally gray/complicated female characters. Queen of Masks is darker than Mine, while Mine has a more polished veneer and perhaps a more optimistic outlook overall.
Both stories focus around women seeking revenge for crimes committed against them in the past. Also, Yoo Sun is in both of them, though her role is more major in Eve. Eve has more romance and the main character is keeping more secrets, while Queen of Masks is a more a story about a tangled friend group where everyone has their own lies and love stories going on but is not exactly romantic.