Since we killed Hades, the God of Death who ruled in the after-life and had created both Hell and Heaven... All that was destroyed. We barely managed to escape from Heaven's grounds as it vanished into nothingness.

I don't know what happened with the countless souls that were in Hell at the time, or what will happen to those who die from now on, but even if they are condemned to an eternal nothingness it's better than what they had. Hades' rules for the after-life weren't exactly fair, even just for stepping on an ant or picking up a flower you would be accused of murder and thrown into Hell, no matter what great deeds you did while alive.