Who said "My fire knows no mercy, for mercy is weakness."?

This quote is attributed to Drogon.

My fire knows no mercy, for mercy is weakness. - Drogon

"My fire knows no mercy, for mercy is weakness."

Drogon Strength

"I am fire. I am death."

"Dracarys."

"A dragon is not a slave."

"I will burn them all."

"Strength comes from within."

"A woman should be proud of who she is."

"A strong woman can overcome anything."

"The only thing I'm good at is killing."