
When Castiel arrived in Season 4, Supernatural transformed from a show about local ghost stories into a much larger story about fate and the war between Heaven and Hell. His introduction marked a turning point, fundamentally changing the show’s tone. Looking back now, seventeen years later, Castiel’s arrival feels like a clear dividing line – there’s a distinct difference between episodes before and after his character appears. The show’s world expanded beyond simple cases in small towns to something much bigger and more complex. What’s great about Supernatural is that it never forgot its roots – it still featured standalone monster hunts, but built upon them with these larger storylines. This balance between familiar, self-contained episodes and the overarching plot kept viewers engaged for years.