Complex sentence: Dan then revealed his secret to all by giving Nate his final chapter to publish in the struggling Spectator, revealing to all that the only purpose of Gossip Girl was the love he had for Serena.
Split into simpler sentences: Dan then revealed his secret to all by giving Nate his final chapter to publish in the struggling Spectator. Revealing to all that the only purpose of Gossip Girl was the love Dan had for Serena.