Serenity is fun and fairly easy to write for (as long as you've got sass and quick wit nailed down!). She's smarter than she looks and generally won't take any bull from anyone. She calls things as she sees them and could care less what other people think of her. To write as her on her blog, you just need to know that she honestly doesn't give a single f*** about who reads her blog or why, and may seem as irritated as she is interested in the comments that her readers may leave. Serenity is the queen bee of her own world where nothing and no one is safe from her blunt opinions.
Please use the current posts on her Tumblr account as examples to get her voice down: http://serenitydoesntcare.tumblr.com