Metal Prinsess Peach was a clone of Peach Toadstool that was mutated. She was first cloned when bowser swiftly kidnapped Prinsess Peach. Bowser was toturing Peach, then when Mario came to save her. He got past all the preset minions and traps. When Bowser realized that Mario was right behind him, he cloned her in case that mario recovered the normal prinsses peach. But while Bowser was attacking Mario, she escaped because she had the same feelings as Prinsses Peach and did not like Bowser, but she did not realize where she was stepping, when she escaped and mindlessly fell into an Abyss of many metal liquids. Instead of being frozen into a Metal statue, this metal addapted to the way she moved and gave her special powers and abilities. Peaches clone got very frightened and ran. But Bowser noticed his clone's new form and power and minipulated the clone that Mario has given her the new form. So, she dedicated her life to EVIL!!!!
One day when Metal Peach was walking along her favorite mountain, a thin 15 year-old in black dress fell out of the sky. It was Rosalina-X! Not knowing the situation, they introduced themselves to each other and became BFFs for life and/or evil partners for life. For the rest of their lives, they both teamed up to destroy Mario and Luigi forever.