Lowest level edit, simply removing obvious filler:

A new kind of vampire is on the prowl.
Something’s wrong with Kitty, a terminally online, slobbish history buff. One random day, she loses all desire to consume—be it food, drink, or media. Things only get worse when she realizes what she must do to solve her problem: produce. A novel idea comes to her, and she writes a bit of it down, but hates each one of her sentences. How can she possibly carve her name into the history she adores with such poor skills?
She finds her answer in the darkest corners of the internet. TB. According to real history, the disease imparts literary prowess. But infecting herself with it proves insufficient. It must spread. And not to just anybody; only to adepts of the craft. Kitty’s quest to feed on others’ literary skill takes her on a misadventure through the lives (and deaths) of a series of authors, deep into their own foul methods of obtaining talent.
And all of that’s just Book One. In a generous two-for-one deal, Book Two is packaged alongside the first. For readers’ consumptive pleasure, a strange, dark, irreverent, and bitingly funny diptych awaits.

Higher level, tweaking word choice and flow:

A new kind of vampire is on the prowl.
Something’s wrong with Kitty, a terminally online, slobbish history buff. She's lost all desire to consume, whether it be food, drink, or--most horrifyingly--the media she once loved. There's only one solution: produce great art herself. But her attempts at a novel are awkward and amateurish. How is she supposed to carve her name into the history she so adores with such a distinct lack of talent?
She finds her answer in the darkest corner of the internet. TB. History has undoubtedly shown that the disease imparts literary prowess. But infecting herself proves insufficient. It must spread. And not to anybody--to adepts of the craft. Kitty’s quest to feed on others’ literary skill leads to strange misadventures through the lives (and deaths) of various authors, deep into their own foul methods of obtaining talent.
A dark, irreverent, and bitingly funny diptych awaits.