"Theo, look at this-" Hermione propped the book up in Theo’s hands and pointed at a diagram stating the uses for Dragon fiendfyre. "Fiendfyre is the only known substance to have no counter curse. If uncontrolled fiendfyre will destroy everything in its path as there is only one known way to control the fire and that lies with the Malfoy animagus gene. In the 14th century Atticus Malfoy tested the theory on numerous objects of dark magic, including but not limited to the highly coveted and elusive soul-tearing magic created for immortality. In conclusion, there was no match for the fiendfyre.." 