The Returned War Hero Became the Empire's Mastermind

After 500 years, I returned to find the empire I saved on the brink of collapse. So, I just planned to fix the country as regent and then go home, but… [Don’t bother being a regent; why not just usurp it completely? I’m quite content just being the ancestor’s concubine.] [Where are you going? You are absolutely not leaving. I’ve waited 500 years; if you run away again, I’ll lock you in the magic tower.] …Am I even going to be able to go home?