A Midgardian's Saga
With this feature, any attack that allows a Reflex save for half damage deals no damage upon a successful save. A failed save still deals full damage. For instance, if a character is hit by a Fireball spell (which allows a Reflex save for half damage) for 30 damage, he or she will take 0 damage on a successful save, and 30 damage on a failed save.
If a character gains this feature and already has Evasion from a different class, then he or she gains Improved Evasion instead.