Who said "Patience is the weapon of the truly powerful."?

This quote is attributed to Grey Worm.

Patience is the weapon of the truly powerful. - Grey Worm

"Patience is the weapon of the truly powerful."

Grey Worm Patience

"I am Grey Worm. I have no name."

"Unsullied do not fear death."

"We are the dragons' soldiers."

"A soldier's duty is to obey."

"Patience is a virtue I'm still learning."

"I may be a redhead, but I'm not a hothead."

"Patience is a virtue."

"Patience is a virtue I never learned."