5. Hana Midorikawa from Prison School

Hana is in charge of keeping watch on prisoners, and she enjoys torturing them and putting them into forced labor.

4. Tsukuyomi from Mahou Sensei Negima!

Tsukuyomi is a child mercenary. While she may look adorable, she is capable of extreme cruelty in combat.

3. Misaki Mei from Another

Misaki is a fifteen year student and is mostly non sociable. Another problem is, nobody knows if she is alive or dead, whether she is a ghost or not, and no one is sure why she wears an eyepatch.

2. Shinozaki Sachiko from Corpse Party

Shinozaki was gentle girl until she died. Once in her ghost form, she became psycho and enjoyed torturing people, treating humans the same way kids treat their toys.

1. Sonozaki Shion from Higurashi

Sonozaki Shion is the evil twin sister of the more gentle Mion. She would deceive people and go on a killing spree.

Disclaimer: Pictures belong to the respective developers of the respective anime shows.