Senior Brother, Please Kill the Demon

[Genius flow + no system + growth flow + relaxed and funny + single female protagonist + protagonist and villain's IQ online] Since ancient times, the human and demon tribes have been at odds with each other. The human race built the Great Wall to suppress monsters outside the misty forest and defended Xichuan to resist the monsters. A hundred years ago, the old demon emperor launched a war and tore apart the Great Wall to suppress demons. The human race rose up to resist. The new human emperor killed thirteen demon kings in a row. The demon emperor was dying and the human emperor fell. Eighteen years ago, during the sixteenth war between human beings and monsters, Li Xian's parents left him alone in the city, and both of them died. From then on, Li Xian grew up with his master, learned formations, learned the art of swordsmanship, and refined poison pills. He was bound to end this chaotic era and kill all the monsters in the world. Become a new generation of human emperor. When I was eighteen Junior sister: Senior brother, monster! Li Xian: Don't be afraid, watch my senior brother kill him with one sword. Senior brother, please kill the demon!