20 parts Complete Summary:
In limbo, Harry doesn't choose to go back to the Forbidden Forest to face Voldemort. He makes another decision and finds himself in a baby's body: little Tom Riddle.
Years pass and intimately bind the orphan and his imaginary friend, in a hopeless and incestuous relationship. Indeed, all the odd events of Tom Riddle's life happen in spite of Harry's presence: could he be the one who provokes them?
This is Tom Riddle's entire life, as close to canon as possible, if he shared his body with Harry Potter (and fell in love with him).
https://archiveofourown.org/works/11244426/chapters/25132107