Harry throws off Fleur's allure without much effort, of course Fleur cannot leave it without knowing how. Read as both lives change from that day onwards and their life becomes linked irrevocably towards each other. Does it end in friendship or love? Or they end up treating each other indifferently as in canon.
What would you see if Harry acted on his feelings. His exploit during the Triwiz.
What if Harry had a chance encounter with one of the influential person in the canon as he was leaving Umbridge's detention. What if that encounter turned his life for the better.
Where Harry has the opportunity to relieve his frustrations on an unexpected person.