Penance was always a part of Monet
- House of X #4 shows that she has the power to transform into Penance at will.◊ When her brother tries to recruit her to rule other dimensions at his side, she mocked his appearance and the fact he's turned into a monster for the sake of power. She then notes he can't walk in public without nauseating people but expects her to turn into a monster for the sake of lording power over freaks in another world. She continues to laugh in his face, and a fed up Emplate traps her in the Penance body. It's possible the form was always apart of her power-set, and Emplate just brought it out with his sorcery. As a form of punishment, and irony of her having a part of her that was equally as non-human as he was. Sadly Monet not being able to deactivate it made it a prison. Eventually she was "freed" from the body and it became it's own entity. However, it may have actually split her very being in two and Penance was another side of her that she'd forsaken due to her brother's abuse. It is possible she has merged back with Penance, and learned to control the form, also reclaiming a lost part of her soul with the development.
- JOSSED: During X-Men Monday #32, Hickman implies that Monet's Penance form is due to some tweaking in the resurrection process. She revealed the form just before getting killed in House of X #4. This also hints that House of X #5 was not her first resurrection by The Five, and as such, she died sometime before the events of Hickman's X-Men.