Dirtaria
Charles had one goal in life: fix the barn roof, pay his workers, and pretend he didn't share blood with the most corrupt imperial family on the continent. As the unacknowledged, banished seventh prince of the Eastern Empire, he was perfectly content living in absolute obscurity on the agricultural fringe.
Then the Emperor provoked a god.
Overnight, the Empire is reduced to ash by Rimuru Tempest, and Charles is abruptly crowned the sole surviving heir. Expecting a swift execution when the terrifying Primordial Demon Diablo kicks down his barn door, Charles instead finds himself forcibly promoted to Vassal Ruler of the newly conquered western territories.
Meanwhile, back in Tempest, an all-powerful slime is having a complete meltdown. Rimuru didn't mean to spare an imperial prince, but watching a dirt-smudged handyman shield a goblin child from certain death just jump-started a heart he isn't even supposed to have. Now, Rimuru has to figure out how to woo a stubbornly independent, deeply traumatized man who thinks his new demonic overlords are constantly plotting his demise.
A post-canon Tensura AU by Dirtaria featuring accidental sovereignty, devastatingly polite demons, and a supreme being who is completely disastrous at flirting.