Hermione Granger and the Hogwarts Champion

Hermione Granger is having a crisis, what with her mother giving her an ultimatum (choose her parents or Hogwarts, basically) and her friendships with her best (read: only) friends faltering at best after months spent not speaking to each other all last term. The last thing she needs is Lilith "Shadow" Gaunt showing up in her life, making it look easy to take all the electives (*without* a time turner), beating her in essays and casting advanced magic like it's nothing. Unfortunately, Gaunt is actually a "temporally displaced" version of Tom Riddle, so someone needs to keep an eye on her, and what are the chances that someone will be anyone other than Hermione?