Who said "Death is just another mission if you're trained for it."?

This quote is attributed to Black Widow.

Death is just another mission if you're trained for it. - Black Widow

"Death is just another mission if you're trained for it."

Black Widow Death

"I'm not the only monster in the room."

"It's never too late to start over."

"We all have our secrets. The question is what we do with them."

"Family is complicated, but it's all we have."

"Death doesn't scare me anymore."

"Death and I are old friends."

"Welcome to my world."

"Death is just the beginning."