Complex sentence: Later, Sapphire saves Ruby from execution by getting themselves safe on Earth, where they form a romantic bond, which they consummate by staying fused as Garnet, and subsequently joined the Crystal Gems.
Split into simpler sentences: Later, Sapphire saves Ruby from execution by getting themselves on Earth safely. On th planet, they form a romantic bond, which they consummate by staying fused as Garnet, and subsequently joined the Crystal Gems.