Actual spoilers for the game
The background to everything is that notRome got nuked repeatedly while they fought several "demons", while being assisted by several gods
>It turns out that the Gods and the Demons are the exact same beings, do actually exist, and have been manipulating mankind for eons just for fun
>What's more, they're really, REALLY pissed because the notRoman scientists tried to trick them into becoming slaves, and now want to either enslave or kill humanity, even the last remaining "good" entity

>The best ending for your character is restarting the process that trapped them in your world, and slaving one of them to your will