Complex sentence: The swan creates a city for Prince Gvidon to rule, but he is homesick, and the swan turns him into a mosquito, in which guise he visits Tsar Saltan's court, where he stings his aunt's eye and escapes.
Split into simpler sentences: The swan creates a city for Prince Gvidon to rule, but he is homesick, and the swan turns him into a mosquito. In this guise he visits Tsar Saltan's court, where he stings his aunt's eye and escapes.