Complex sentence: The Titans battle hordes of guardian demons while Raven gets the crystal, but an undead Ra's al Ghul shatters it; he was made Trigon's vassal following his death, since the Lazarus pits were created by him.
Split into simpler sentences: The Titans battle hordes of guardian demons while Raven gets the crystal, but an undead Ra's al Ghul shatters it. He was made Trigon's vassal following his death, since the Lazarus pits were created by him.