Complex sentence: Marzanna, Mara, Murava, Morana, Moréna or Morena is a Slavic goddess with an unclear function, most often believed to be a goddess of harvest and witchcraft.
Split into simpler sentences: Marzanna, Mara, Murava, Morana, Moréna or Morena is a Slavic goddess. She is most often believed to be a Goddess of harvest and witchcraft.