Is Ms. Victoria a Feral or something? Does she has to hide her race to keep her job? But don't ferals go to her school?
That aside, exactly how involved is Double usually in the affairs of the Skullgirl? With Marie, she's acting directly and interacting with the Skullgirl herself, which seems unusual given her main skillset of being a mimic subservient to the Skullheart/Gods itself. In the past she seemed more covert, what with the gift of the Skullheart to the Contellios and what not. I'm also pretty certain that making Queen Nancy a Skullgirl was of Double's doing. It just seems to me that Double doesn't interact face to face with the Skullgirls that often.
I have no evidence for that assertion except perhaps a desire to keep the Skullheart lair a secret. Has the Skullheart lair always been in the same place? Or was the Trinity church just the most recent location? Judging from Eliza's reaction and subsequent power up, is this a major storage of power from the Skullheart? Or does the Skullgirl herself make her own lair? Marie doesn't seem that connected to the Church, but perhaps it's just a convenient location? Or was it already there? Are there other places like this around the world? Are Skullgirls supported by the forces of the Skullheart as well as Marie is?
While I'm fairly certain each Skullgirl has their own particularities, and I'm basing this on little evidence and my gut, I'm thinking Marie is special and required special treatment, even bypassing the usual individual cases each Skullgirl poses. I'm thinking that Marie's powerful willpower made it difficult for to provoke a rampage out of her, opting instead for focused murders against the Medici. Double had to intervene directly. If there really is one and only one lair for the Skullheart, and if the forces of the Skullheart rarely help the Skullgirl herself beyond the initial wish, then having to allow Marie access to the lair itself is a sign that either Marie is so difficult, a risk like that had to be taken or the lair has now become disposable because the Skullheart's plans are near fruition...
Double is taking a risk in exposing herself, as it seems that most people do not know of her...it's...? existence, which is clearly beneficial. Revealing that a shapeshifter is directly driving the Skullheart's agenda would make future manipulations much more difficult. Again, I'm not sure if the Skullheart lair is even special or even an intentional effect, but Double's actions were made because of the difficultly of the Skullgirl or a sign the Skullheart agenda is reaching endgame.
Marie was chosen to become the next Skullgirl, this was no accident. But why chose someone with the willpower to resist the Skullheart's corruption? Perhaps it was a necessary drawback or even a benefit to select someone with more concrete goals than 'Save my family' or 'World Peace'. In fact, the goal of destroying the Medici may, in fact, be exactly what the Skullheart wants?
I raised the point that the Medici are likely in charge of the post-Skullgirl relief, so destroying them would make the inevitable rampage all the more potent. It seems that the Skullheart has been particularly more prolific lately. From possessing a famed family of Opera singers, to THE QUEEN OF AN NATION, it looks like the Skullheart is trying to break the public's will. And even with the possession of a queen, the public still managed to get by, probably because of the Medici. Disgusting as it sounds, the public relies on the Medici as some sort of order in these times of chaos, especially now that faith in the Canopy royalty has been deeply shaken. So if you had a Skullgirl whose wants to kill the Medici full stop, then wouldn't the last bit of stability society has, amoral and vice ridden it may be, just collapse?
Yes, I'm fairly certain that the Skullheart possessed Queen Nancy as a setup to put the Medici on top of the world, just before cutting them down. In fact, I'm pretty sure the Skullheart even helped build their empire just so it can tear it all down onto the world's head. Force the Canopy Kingdom to embrace underworld scum, the Medici, just to destroy them anyways is a one two punch that would give the Grinch the giggles.