Who said "Fire is the purest form of change."?

This quote is attributed to Daenerys Targaryen.

Fire is the purest form of change. - Daenerys Targaryen

"Fire is the purest form of change."

Daenerys Targaryen

"I am the blood of Old Valyria. I am the dragon."

"A dragon is not a slave."

"I will take what is mine with fire and blood."

"The night is dark and full of terrors, but so is the day."