Comprehensive Comic: the Demon Lord of Black Sun Castle

When you travel to a different world and open your eyes, you will see a medieval castle. The black sun above your head burns the sky to pieces, and the grassland outside the city is connected to the bloody ridge. Two rows of maids respectfully called him master, but before he could ask where this was - the system popped up a prompt: The castle's defense shield had 3% energy left, and the monsters of the black sun would crawl out to eat people after dark. He turned to look at the maid: Do you have weapons? They all pulled out long knives from under their skirts.