Alert : Some spoil for someone new that have problem
You need to restart on your own by button Well... you go for main story route that's unfinish andddd there are one for apothus but you must lose to him. Try to do something involve cult for ending. And there are something with imp.
I can only hint like this since it's for achievement.
Oh right, I will answer if i can instead developer because he must busy with update.
So ask something that not require spoil ending.