Complex sentence: A hole was torn in the fabric of space-time when Nightcrawler and Dark Beast from the Age of Apocalypse used the Dreaming Celestial to try and get back home which released three energy-consuming monsters that began to threaten the entire existence of both worlds.
Split into simpler sentences: A hole was torn in the fabric of space-time when Nightcrawler and Dark Beast from the Age of Apocalypse used the Dreaming Celestial to try and get back home. Three energy-consuming monsters were released and they began to threaten the entire existence of both worlds.