What is tu fui ego eris?

"Tu fui ego eris" is a Latin phrase that means "you were what I am, I will be what you are." It refers to the idea of the cycle of life and death, where someone who is alive now will eventually die and become what someone else currently is, while that person will in turn become what the first person used to be. This phrase has been used in various contexts and media, including literature, music, and film. It is often associated with the theme of mortality and the inevitability of death.