Hired to be the oncologist of Ichirō Yashida, Viper helped him develop the samuri suit that would later sustain his life. She then planted a parasite in the body of the Wolverine, suppressing his healing factor. However, due to her allegiance with Yashida, during the Battle of Yashida Tower, the Viper was killed by Yukio.
The Vipre possessed enhanced intelligence and the ability to create toxins. She also had immunity to all toxins and could create the antidote for any toxin.