Start by Pulling Out the Sword in the Stone

Ai Li was reincarnated into a parallel world, where bloodline was revealed and the strong were respected. While traveling abroad, he accidentally summoned the Sword in the Stone, an artifact that would rule the country until the sun never sets. Half an hour later, the eldest princess of the royal family descended from the sky and pointed her sword at Aili: Either marry me or declare war until the sun sets!