I wonder if she hates a boy name John Connors. Introduced in New Mutants (Vol. 2) #2 (2003) by Christina Weir, Nunzio DeFilippis and Keron Grant, Sarah Kincaid was an ordinary girl until her powers mutants manifested, turning her body into a silver liquid metal. Wanting her to learn to control her powers, her parents sent her to study at the recent opened Xavier School. There she became friends with Hellion (Keller) and became close with Whither, especially when it was discovered she was immune to his death touch. The three along with Dust, Rockslide and Tag, form the Hellions training squad under Emma Frost. An encounter with the Kingmaker made her realize that her parents were ashamed of her and disowned her.

After M-Day, she was one of the 27 students that still had their powers. After dealing with William Stryker and his Purifiers, Emma Frost held a battle royale of the remaining students. The victors, including Mercury, were made into the New X-men, a team that were being trained to become the next X-men in case the main team died. She would become a person of support for X-23, given Wolverine’s daughter a source of emotional dependency. When she learned that Emma Frost was going to force Laura to leave the school, she took Laura to a coffee shop. However, it was bombed by Kimura who kidnapped Cassidy. At the Facilty, she was tortured and some of her skin was taken to make part of Predator X. She was eventually rescued and taken back to the institute where she received trauma therapy. While recovering in bed, she was teleported to Limbo along with the rest of the student body. She helped battle Belasco with Dust.

During Messiah Complex, the New X-men went to battle the Purifiers to protect the new baby mutant but during the battle Pixie teleported them away. She was later seen fighting Predator X with the rest of the team. After the X-men broke up and later set up in San Francisco as a safe haven for mutants, she would join them. She was later seen fighting against the Skrull invasion during Secret Wars. She was reunited with her father when Norman Osborn both bribed and blackmailed him to discredit the X-men as kidnappers. However, Deadpool, trying to impress the X-men, attempted to assassinate her father. Her father then revealed the truth on live-TV, discrediting Osborn.

Skipping a bit because she became more of a background character then, she sided with Wolverine following the schism. She began attending Wolverine’s school alongside her team mates. After Age of X, she went with the rest of mutantkind to Krakoa. There she was seen kissing Bling!, confirming herself to be gay. She was later seen dating Loa and despite some traumatic interference from Pixie and Legion, they seem to still be together.