For the record, Angel really does have season arcs. And there are specific characters that can easily be viewed as big bads.
It's just that Wolfram and Heart are an overarching concept and season 1 in particular is more episodic than any other season (or any season of Buffy for that matter), so it doesn't have as much build-up to the finale.
It's just that Wolfram and Heart are an overarching concept and season 1 in particular is more episodic than any other season (or any season of Buffy for that matter), so it doesn't have as much build-up to the finale.