Who said "Fear is the enemy. I have learned to kill it."?

This quote is attributed to Grey Worm.

Fear is the enemy. I have learned to kill it. - Grey Worm

"Fear is the enemy. I have learned to kill it."

Grey Worm Fear

"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."

"Face your fears with courage."

"You can't live your life in fear."

"Snakes. Why'd it have to be snakes?"

"Fear is just another obstacle to overcome."