Complex sentence: Słowacki's works, situated in the period of romanticism in Poland, often rely on neologisms, use fantasy, mysticism and symbolism and feature themes related to Poland's history, essence of Polishness, and relation to a larger universe.
Split into simpler sentences: Słowacki's works, situated in the period of romanticism in Poland, contain rich and inventive vocabulary, including many neologisms. They use fantasy, mysticism and symbolism and feature themes related to Poland's history, essence of Polishness, and relation to a larger universe.