The ritual had changed something - of course it was only meant to protect them from blood magic, but the finality of it all set a clear precedent in their relation to each other. They would forever depend on the other for safety - it was one of the largest acts of trust Hermione had ever demonstrated. Was she a fool for making such a life-lasting decision? If it aided at all in the defeat of Voldemort, she would do it a million times over.