[s4e23] We Are The | Flash

While the Enlightenment is stopped, the victory isn't free. The episode marks a turning point for several characters:

The finale is most remembered for revealing the "Mystery Girl" as Nora West-Allen, Barry and Iris's daughter from the future. Her arrival, having helped Barry destroy the falling satellite, introduces the "big mistake" that sets the stage for Season 5. It reinforces the show's recurring theme: every time a speedster fixes a problem using time travel, they create a new, often more complex, disaster.

He loses his "super-intelligence" but gains a balanced emotional life, ending his arc of defining his worth solely by his IQ.