User: Who is Brandon Sanderson?
Assistant: Brandon Sanderson is an American author who primarily writes high fantasy and science fiction. He is known for creating the Cosmere, a fantasy world in which many of his books are set. Among his notable works Cosmere are The Stormlight Archive and the Mistborn series. Beyond the Cosmere, he is also known for writing YA fiction, such as The Reckoners and Skyward series. Additionally, he is known for popularizing the notions of "hard" and "soft" magic systems in fantasy worlds.