Does Hidden Blade's "draw 2" effect still resolve if the targeted unit is moved away from the battlefield (e.g., by Flash) before Hidden Blade resolves?

Ruling: No, the draw 2 does not happen if the unit is moved away from the battlefield before Hidden Blade resolves, because the spell cannot identify the controller of a unit that is no longer at the battlefield.

Nuances:

• If the unit was saved by an effect like Zhonya's (which presumably keeps it at the battlefield or maintains it as a legal target), the controller would still draw since the target was legal at the beginning of resolution
• Spells don't fizzle for their target moving in Riftbound, but Hidden Blade specifically needs to reference the unit at the battlefield to execute the draw effect
• If the unit is moved back to the battlefield before Hidden Blade resolves, the effect would go through