Tone: generally mischievous, bubbly, for evil moments the sounds need to be sharp, deep.
An example of what we're looking for is Sima Yi from Fate Grand Order:
https://www.youtube.com/watch?v=BZb68G2A-l8

Twin sister to the fabled Emiri Onishi. Friendly and mischievous, Shizuyo tends to draw attention to herself, which she absolutely enjoys. You can even say she is the mirror image of her sister, in personalities and in attitudes.