"Your name was stolen? I see... Well, I guess that happens from time to time..."
Vivian is the youngest of the Shadow Sirens, a group of witchly sisters who are in employ of the X-Nauts. Despite working with the group, they seem to have their own, darker agenda. Despite this, Vivian is the sweeter, nicer sister of the group. Often abused and belittled by Bedlam, she is a little more than depressed a lot of the time. She is blamed for all of the failures they suffered, despite having little to do with the mistakes. She went on to travel with Mario after he showed her an act of kindness and helped him with her ability to hide in the shadows.
Her main, notable ability is her pyrokinesis: She utilizes the element of fire in battle, from using "Shade Fist" to catching multiple enemies on fire with "Firey Jinx". Another of her abilities, "Infatuate", involves blowing a magical kiss to her foes and confusing them.