There Are Aliens in My Brain

As the saying goes, if you are wandering in the world, how can you not get stabbed? If you can't fight in a single fight, or if there is no one in a group fight, what should you do? At this moment, a group of mini aliens descended from the sky and said they would become our little brothers, but the condition is that they must settle down in our head, build houses, build cities, form armies, and develop high civilization in our head. Damn, this is our head. Is there such a mess? But...