Chachazero

Chachazero (チャチャゼロ) is a magical doll that was Evangeline's Ministrum Magi before Nagi cursed the Dark Evangel with Infernus Scholasticus. She looks like a small and childlike version of Chachamaru. Unlike Chachamaru (Evangeline's current Ministra Magi), who is powered by a minimal amount of magical energy that Evangeline still has and a spring, Chachazero needs to be powered by quite a large amount of magic, which mainly came from Evangeline. Because of the curse, she can talk on her own, but cannot move unless there is a large concentration of magic in the area, which is the reason why Evangeline relies on Chachamaru. Chachamaru is polite kind and well mannered. However, Chachazero is rude, abrupt, a bit of a whiner and sometimes bloodthirsty. She is always complaining that she cannot move and that her master has become too soft and not so evil. This is because Chachazero enjoys killing things and seeing things get killed. When she fights, she uses two daggers, and sometimes, a giant sword larger than she is. She is sometimes seen riding on Chachamaru's head or carried like a marionette by Evangeline. In areas with the high amounts of ambient magical energy, such as Evangeline's resort, or during the Mahora Festival, Chachazero is able to move about on her own like a small child. She was also able to move about freely in Kyoto, since Evangeline's full powers were unsealed. Chachazero also seems to get along well with Chamo.

Mahō Sensei Negima! (1st Anime)
While she can be vindictive in the manga, in the anime Chachazero takes on a minor and childlike role; appearing in the memory and voicing Evangeline's request for Nagi to "become mine Evangeline's" and the recurring dream of Evangeline's past defeat at Nagi's hands.

Negima!?
In Negima!? Neo she and Chachamaru gain more human appearance as both of them don't seem so robotic. She also helps with Negi's training and she is stricter than Evangeline.

UQ Holder!
Chachazero makes a cameo appearance in the beginning of Chapter 1, Chapter 81 and Chapter 129 of UQ Holder! Later she makes an actual appearance in Chapter 137, and is now kept by Chamo. It's revealed by Chamo that her body had been destroyed a long time ago, and Chamo tried to fixed her body and she's still left unconscious since the incident.

Later in Chapter 147, Chachazero finally awakens from the long unconsciousness thanks to Evangeline giving some magic power to her. Chachazero showed Evangeline 700 years ago flashbacks where Evangeline meets Touta once again at Dana's palace. Chachazero noticed Evangeline has a crush on Touta and keeps telling her to show her love on Touta now, though Evangeline somewhat disagrees for some reason. When Touta comes into Evangeline's room, she shows a flashback of how Touta is born to both Touta and Evangeline.

Trivia

 * At around the time of the Mahora Academy School Festival, Chachazero and Chamo had formed a friendship and would sometimes go out drinking together after school.