Chachazero is a magical doll who served as Evangeline's Ministrum Magi before Nagi cursed the Dark Evangel. She's basically a smaller, childlike version of Chachamaru, but where Chachamaru runs on minimal magical energy and a spring mechanism, Chachazero demands a huge amount of magic to function—which is why Evangeline eventually switched to the more practical Chachamaru instead.
The curse left her able to talk freely, but movement is another story. She can only really move in areas saturated with magical energy, like Evangeline's resort or during the Mahora Festival. She's also gotten around fine in Kyoto after Evangeline's powers got fully restored. When she's stuck without enough ambient magic, she usually ends up either riding on Chachamaru's head or being carried around like a puppet.
Personality-wise, Chachazero is basically the dark mirror of Chachamaru's politeness. She's rude, whiny, and abrupt—mostly because she genuinely loves violence and gets frustrated that her master has gone soft. In combat, she wields two daggers and meat cleavers, and sometimes swings around a giant sword that's basically her own size. She's apparently got a weirdly good friendship with Chamo, and the two are constantly hanging out, making comments, and eating while they watch drama unfold between Negi and Evangeline.
The anime toned her down significantly, giving her a more childlike, minor role where she mostly pops up in Evangeline's memories and dreams, occasionally chasing butterflies. In Negima!?, things get weird—Evangeline commands an entire army of Chachazeroes during her fight with Nagi, and in another episode, one even helps distract a Dark Seed Fairy so the class can rescue Negi the Chupacabra.
Content compiled by AnimeList.moe from publicly available sources.
