Who said "Death is just a transition I've already practiced."?

This quote is attributed to Nebula.

Death is just a transition I've already practiced. - Nebula

"Death is just a transition I've already practiced."

Nebula Death

"I didn't ask for this life."

"You're welcome."

"I will kill you slowly."

"Gamora may have stolen your money, but I will steal your life."

"Death doesn't scare me anymore."

"Death and I are old friends."

"Welcome to my world."

"Death is just the beginning."