Temporal Echo Blade

With a command that reverberates throughout the ages, you summon forth a spectral duplicate of yourself that wields a shining blade of psychic energy. This temporal echo appears in a line extending 60 feet from you and can pass through solid obstacles, attacking all targets in its path. Each creature within the line must make a Dexterity saving throw. On a failed save, a creature takes 4d12 psychic damage and suffers a disorienting effect that halves their movement speed until the end of their next turn. On a success, they take half damage without the movement penalty. The temporal echo moves with impossibly swift strikes, as if existing both in this moment and in others, delivering a burst of unpredictable energy with each swing. Once the attack is resolved, the echo dissipates back into the flow of time, leaving a lingering shimmer of potential futures.