One aspect I love about the Marvel Cinematic Universe (MCU) is how each film tries to differentiate itself from what came before and how each film pushes forward a different theme/genre within the universe ultimately expanding on what we know so far. Sure there is a formulaic approach underlying the MCU but the surrounding material that fills the variables does its best to characterise the film as unique with a distinct personality. Doctor Strange introduces the relevance of magic (and the multiverse) within the MCU and the dark forces present eager to sink their darkness within the Earth and its populace.
Doctor Strange is a story about a genius surgeon who loses the use of his hands after an accident. Out of options and possibilities within medical science, he finds hope within a similar case that leads him to Kathmandu. There he meets the Ancient One and learns that what he knows about the world is just a fraction of actuality.