Does Hidden Blade give the draw if the unit doesn't die (e.g., with Zhonya's Hourglass or if Retreated)?

Ruling: Hidden Blade gives the draw if the unit survives with Zhonya's Hourglass because the unit is still in play and its controller can be established. If the unit is Retreated or moved to base before Hidden Blade resolves, you do not draw because it's no longer a legal target at a battlefield.

Sequence:

• Hidden Blade targets a unit at a battlefield
• Cards check legality on finalize and on resolution
• If the unit is still in play when resolving (even if it didn't die due to Hourglass), the controller can be established and you draw
• If the unit is no longer in play or no longer at a battlefield, it's not a legal target and you don't draw

Nuances:

• Zhonya's Hourglass is unique because Hidden Blade already resolved with a legal target at a battlefield before Hourglass triggers
• If the unit is moved to base via a flash effect before Hidden Blade resolves, you wouldn't draw