Vivio Takamachi

A mysterious child who was found with a relic and rescued by Caro and Erio. She becomes fond of Nanoha and vice versa. Later in the series Nanoha have taken her in and Fate helps take care of her. After the Strikers TV series Vivio still refers both Nanoha and Fate as "mama" but Nanoha said in the Strikers Sound Stages that Vivio refers Fate as an older sister now more than a mother because Fate is keeping her distance to Vivio since Nanoha adopted her though this is confined only to this instance. Vivio also refers Erio and Caro as her relatives. Vivio has complete  heterochromia, her right eye being green while her left being red. She is a man-made mage, made from the DNA of Sankt Kaiser, and is kidnapped by the numbers to use her powers, manipulating her mind to turn her against Nanoha. Nanoha manages to defeat the Numbers and free their grip on Vivio, returning her to normal. She is named for the  Subaru Vivio. Nanoha tends to be strict with her, while Fate tends to spoil her giving both "moms" a little role reversal personality-wise. When in her adult form, Vivio wore a black-and-blue barrier jacket. She later becomes the protagonist of  Magical Girl Lyrical Nanoha ViVid, Nanoha gave her an intelligent device which Vivio named Sacred Heart (nickname Kris) after Nanoha's Raising Heart. It's a crystal similar to Raising Heart stored inside (and animating) a stuffed rabbit. When transformed, she takes her adult form, but with  a white barrier jacket styled after Nanoha's. She also a Chosen One.