After being forced to step down, the once-annoying nun eloped with me.

After establishing a unified human empire, Yang Hao was unjustly impeached and removed from power due to the unequal distribution of benefits to nobles, popes, and landowners. None of those he supported spoke out against him, or rather, they were unable to speak out. This event is known as the "Silent Exile" event.
After returning to the village where it all began, feeling deeply humiliated, he was greeted not by the friends who had helped him before, nor by the village chief who had once saved his life, but by the annoying Sister Teresa, with whom he had never gotten along.
"Did you come here specifically to mock me?"
"It's certainly amusing to see you looking so pathetic, but there's nowhere for you to go in this country anymore. Here, this is bread for a homeless, skinny little dog. Don't think about it anymore; those bad women have nothing to do with you. Come with me."
...Ten years later.
"I've come to take back what's rightfully mine."
When the allied forces of the elves and demons attacked the human empire, which was torn apart by internal and external troubles, every human could see that the one being worshipped as king by the elves and demons was none other than the regent who had been driven out by them years before, along with the nun who accompanied him.