before anything, keep in mind that, all we know of MC's power, is pure theory and conjecture, as the only person who truly knows what his power is, is Gramps, but he won't tell us. what i can say for sure, is that "Shatter" is only half of his true power, that was split during the Act 1 ending event.
my understanding on Chloe, is that her "true self" no longer exists (as of now, because Arc said it might be possible to bring her back). what we see, as the "outbreak", would be the "original personality" we ordered the Shattered Chloe to have, as we told her to act normal around others. not to mention, there's the assassin fey inside her, and the outbreak could be it too. another factor to ponder, is that Chloe (and Gwen) were hit with an overcharged Shatter/Awaken, so they're unique. if you don't remember, we can't get them pregnant as of now, BUT you CAN get Luna pregnant, even if you shatter her.