If Hidden Blade targets a unit and Sett's replacement effect saves it by recalling it instead of killing it, does the unit's controller still draw 2 cards?

Ruling: Yes, the unit's controller still draws 2 cards. When Sett's replacement effect recalls the unit instead of killing it, Hidden Blade can still track the controller of the legal target it began resolving with, so the draw effect still occurs.

Nuances:

• If the unit is bounced to hand or removed before Hidden Blade begins resolving (e.g., via Gust in response), then Hidden Blade has no legal target at resolution and no one draws.
• The key distinction is that replacement effects modify what happens during resolution, but the spell still resolves with a legal target whose controller can be determined.
• This ruling applies even when replacement effects move the unit to a different zone (like base or hand) during resolution, as long as the target was legal when resolution began.
• The interaction of replacement effects with "last known information" rules is still being clarified by the design team for edge cases.