The Uncanny X-Men| The Rebels |The Six Pack | Others | Bad Guys

Tessa

Real Name: Tessa Niles

Powers: Telepathic abilities, Advanced memory storage and total recall, Senses mutants, Initiate and unleash potential mutations within others

History: Tessa Niles, was recruited by Charles Xavier as his sixth member of his original X-Men, when she was only a teenager. However, Xavier did not ask for her to join the ranks of the team, but to infiltrate the Hellfire Club. She agreed and joined the Hellfire Club, as Sebastian Shaw's assistant, or more his shadow, under the name Tessa.

At one point, a young Elisabeth "Betsy" Braddock, before she joined the X-Men, worked for the British Government. She, too, had been sent to infiltrate the Hellfire Club, but was warded off by Tessa; who was both trying to protect Psylocke from the power-hungry people within the Inner Circle and from stopping the British Government's mission from endangering her own.

As Shaw's assistant, and as a side member of the Hellfire Club, Tessa and the X-Men came face-to-face many times in battle; however the X-Men for the safety of the mission did not know that Sage was an X-Man. On one occasion, her and Xavier were both captured by Donald Pierce, who was planned on tapping both their minds and absorb all the data in their brains. His plans were foiled by the Hellfire Club, and Tessa dealt with Pierce. Later on in a battle with the New Mutants, she was possessed by Karma, who said Tessa is like a living computer with remarkable willpower.