[s3e20] I Know Who You Are Review

In the milestone episode (Season 3, Episode 20), The Flash finally unmasks its season-long antagonist, Savitar , revealing him to be a future, scarred version of Barry Allen . The Big Reveal

The reveal recontextualizes his frequent claim, "I am the future, Flash." Without a comma, he was literally stating his identity: " I am the Future Flash ". [S3E20] I Know Who You Are

Savitar is a future Barry Allen (specifically a time remnant created in the future) who survived the battle against Savitar but was shunned by Team Flash, eventually driving him to madness. In the milestone episode (Season 3, Episode 20),

Barry reaches this epiphany after realizing that Savitar ’s constant knowledge of their every move isn't just foresight—it's memory. The "God of Speed" had lived through these exact events when he was Barry . Barry reaches this epiphany after realizing that Savitar

The Flash recap: Season 3, Episode 20 - Entertainment Weekly