Preparation at it's Finest

You die and are reincarnated. Great. You're now in the world of Harry Potter. Fantastic. You have to relive your childhood with everything it entails. Less good. You're the brother of Tonks. Amazing. Only, you know that she dies, and you've gotten a bit attached. So, what can you do but ensure that she lives. So what if you're not merlin reborn, you know the future. SIOC