I, the Demon King, became a girl!! (Rewrite!)

The Demon King was about to conquer the world when the Goddess gave three sacred weapons to the humans. With three heroes wielding those powerful weapons, the tides of war changed and now the Demon King was dying. In the afterlife, he met the same Goddess who reincarnated him into a girl. Where will the Demon King’s life lead him and why did the Goddess reincarnate a dangerous being? (In the process of rewriting)