The World-Ending Tyrant Refuses to Unhand Me

I woke up entirely by accident, dangling from a crystal chandelier suspended above the royal beast pits. Below me, covered in blood and glaring with enough hatred to melt solid marble, was Tigranes - the royal family's cursed slave. According to the fantasy novel I'd transmigrated into, this boy was fated to slaughter the royals - myself included - before saving us from an apocalyptic demon. My mathematically perfect survival plan? Drop down, claim him as my personal servant, and treat him with exactly enough calculated kindness to ensure my immunity when he eventually usurps the throne. For years, I fed him, educated him, and shielded him from the manipulative, fake Saintess Phaedra. It was a flawless strategy. The time-skip arrived, Tigranes took the throne, and I packed my bags to retire to a quiet island. There was just one massive miscalculation. Tigranes didn't just want me to stay; he barred the city gates and cheerfully promised to plunge the entire continent into molten ash if I took a single step outside. And that separate apocalyptic demon plotline? Turns out, the demon is him. Can I logic my way out of a bittersweet romance that threatens to end the world?