Complex sentence: The main proponent of the style was John Eberson, who designed the first atmospheric prototype, The Indiana Theatre, and before his death designed around 500 in the US and around the world, personally selecting the furnishings and art objects.
Split into simpler sentences: The main proponent of the style was John Eberson, who designed the first atmospheric prototype, The Indiana Theatre. Before his death designed around 500 in the US and around the world, personally selecting the furnishings and art objects.