Complex sentence: After the studio's closing, the Hemdale library was incorporated into the Orion Pictures output now owned by Metro-Goldwyn-Mayer, which ironically originally released many of Hemdale's films.
Split into simpler sentences: After the studio's closing, the Hemdale library was incorporated into the Orion Pictures output now owned by Metro-Goldwyn-Mayer. Orion ironically originally released many of Hemdale's films.