Real Name: Monet Yvette Clarisse Maria Therese St. Croix
First Appearance: Uncanny X-Men #316 (twins as Monet) / Generation X #1 (Monet as Penance) / Generation X #40 ("real" Monet)
Relatives: Ambassador Louis Cartier St. Croix (father), mother (identity unrevealed; deceased), Marius St. Croix (brother; Emplate), Nicole St. Croix (sister), Claudette St. Croix (sister)
Mutant Powers: Superhuman strength, flight, night-vision, super-hearing (?), photographic memory, telepathy, invulnerability against physical harm, and super-human speed. It has also been hinted that M is capable of "supping" on other mutants, draining their energy, much like her brother, Emplate.
History: The daughter of the rich and eccentric Ambassador St. Croix (of Xavier's Mutant Underground fame), Monet was a spoiled child. She was "daddy's little girl" - Cartier favoring the over-achieving Monet over older brother, Marius, and younger twin sisters, Nicole and Claudette. Being spoiled, Monet was, naturally, arrogant and pompous. Tragically, it has been revealed that Marius was, in fact, responsible for their mother's death. When his mutant power first manifested, and his mother tried comforting him, Marius instead supped on her (Mrs. Saint Croix is a mutant?) and killed her, knowing full well what he was doing. Marius was, of course, then kicked out of the house by their father, and did not come back for quite some time.
Everything seemed to be fine in the St. Croix residence, until the day Marius, who had seemingly just come from another dimension and altered himself physically, asked Monet to join him on his quest to conquer the world. Monet, having no desire at all to rule the world, declined Marius' "offer" - in fact, she went a little too far, and teased him about his appearance. Finally having enough of his sister's big mouth and attitude, Marius transformed Monet, apparently through magical means, into a red-skinned, untouchable, mute creature, unable to use her own mutant powers. From that moment on, Marius referred to his sister as "Penance" -- Monet's own sort of penance for her 'holier-than-thou' attitude.
The second after Monet's transformation into Penance, the twins - Nicole and Claudette - walked in on Marius and the red creature (who was not known by the twins to actually be Monet). Angry that Marius returned home despite their father's protest, the twins used their powers to banish their brother to another dimension. As Marius was being transported to that other dimension, he told Penance to come with him, as he is the only one capable of reverting her back to her original body. Penance agreed, and came with Marius to the other dimension. However, Penance never was reverted back to Monet. Instead, Marius, now calling himself Emplate, used his very sister as his 'meal' -- feasting on her genetic marrow for energy.
Back at home, the twins were left confused as to who the red creature was with their brother. They did, however, know that Monet had mysteriously gone missing. Afraid their father would break down, and the household would fall apart, the twin sisters merged bodies and replicated Monet. Everything about the twins' version of Monet was like normal, including her physical body, personality, and powers. Everything would have been perfect, if it weren't for Claudette's autism. Since both the twins' personalities were combined, Claudette's autism would sometimes take effect, leaving "Monet" in catatonic stupors.
Concerned of his favorite daughter's constant "black-outs", Cartier St. Croix enrolled 'Monet' in Xavier's School for Gifted Youngsters. While the Monet-twins happily studied at the Academy, the true Monet was suffering as Emplate's main sustenance. In fact, Marius fed off of Penance so much that he permanently gained her physical attributes - 'spikey' hair and claws. Penance ended up suffering at the hands of Emplate (no pun intended) for several years before Gateway would rescue her, and bring her to Generation X. Unable to communicate, the physically deprived and drained Penance was a complete enigma to Generation X, with Penance was just as riddled by her surroundings. (Note: The Monet-twins still were not aware of Penance's true identity.)
Months after the arrival of Penance, Emplate returned to the Academy to reclaim his 'meal'. Extremely angry that he has been deprived of his main sustenance, he and his newly formed Hellions stormed Generation X. While there, he revealed to Generation X that 'Monet' is really his sister. Unfortunately for Emplate, Generation X, with the help of Bishop, defeated him and saved Penance.
Later on, it was finally revealed that 'Monet' was truly Nicole and Claudette in disguise. While in a battle with Prime Sentinels, 'Monet' was blasted by a Sentinel, and buried under a pile of debris. When teammate Synch cleared off the rocks, he did not find *one* M, but two! However, despite their cover being blown, the twins still did not explain why they masqueraded as Monet in the first place.
It would be soon after the twins' revelation that Emplate came back to terrorize the young mutants. During the battle, the twins merged with Emplate, creating a new persona, called "M-Plate". When the three of them separated, they knew each others' secrets... including what really happened to the true Monet St. Croix! The twins kept the secret for a short time, though Synch eventually found out when he accidentally synched with the twins' telepathy and found out their secrets. Everett managed to convince Nicole to finally reveal the secret of Penance, and the entire truth, to the rest of the team.
Immediately after Nicole revealed to Generation X who Penance really was, the twin sisters merged back together to form "M". Using their combined powers, the twins somehow switched bodies with Penance, leaving the twins in the Penance body, and Monet in her own, true body. At long last, Monet St. Croix was herself again! However, that left the twins trapped in Penance's body for quite awhile. It wasn't until Jubilee caused an explosion which, once again, seperated the twins from each other, and left the Penance body to become its own being.
Recently, Cartier St. Croix finally visited his three daughters in Massachusetts, after having heard that Marius was severely injured. He also wanted to see his daughters, and make ammends with them for having neglected them for so long. However, his way of showing he cared and listened to Monet's needs was to transfer her out of the Academy! Apparently, Monet had been telling her father how she hated being in the Massachusetts Academy, so he transferred her to another exclusive boarding school in the Swiss Alps. Monet seemed to be adapting fine to her new school, but she soon found out that the headmaster there was really a vampire, who was responsible for a number of deaths in the school. Monet quickly defeated him, and the school was burned down. After, M had a choice to go to any school she wanted, but she chose to return to the Massachusetts Academy, where she continues to stay today.
Currently, Monet and fellow teammate Everett have started seeing each other romantically, despite Jubilee's understandable objections. However, as we all know, their relationship will not last long at all, since in #63, it is revealed that Everett did not live through the "Shockwave" (current) storyline. Since Everett's death, Monet is no longer focused in her training sessions, and has lashed out at opponents during battle. Although the other members of Gen X seemed to have moved on already, Monet is still feeling the pain of Everett's death. However, the why's and how's of Everett's death remains to be answered. Could it be possible that Monet had something to do with it? We just have to wait and see...
(To find out the issues in which these events happened, read the Key Issues.)