Complex sentence: Merrick, a powerful Mayfair witch made vampire, agrees to help and it is revealed that the now blood-thirsty Goblin, who looks exactly like Quinn, is in fact a baby boy's spirit--the spirit of Quinn's stillborn twin brother.
Split into simpler sentences: Merrick, a powerful Mayfair witch made vampire, agrees to help. It is revealed that the now bloodthirsty Goblin, who looks exactly like Quinn, is in fact a baby boy's spirit--the spirit of Quinn's stillborn twin brother.