Blast to the Past

The future was over. The apocalypse struck in the form of a goddess released from her prison. No one was safe and the world came to an end. One person was left alive, and decided to save the future. By returning to the past.

But how would he manage when everywhere he turns, all he sees is death and destruction laid over everything?

What is he to do when he realizes the one he loves has also returned to the past with him? How will that affect his plans?