Complex sentence: Green Lantern then attacks the kidnapper, revealing itself to be a monstrous Parademon, and just as he is about to get crushed, Batman appears and grabs the Parademon from one rooftop to another, demanding answers as to what it was doing at the docks.
Split into simpler sentences: Green Lantern then attacks the kidnapper revealing itself to be a monstrous Parademon. Just as he is about to get crushed, Batman appears and grabs the Parademon from one rooftop to another, demanding answers as to what it was doing at the docks.