If I use Temporal Portal to give Hidden Blade the Repeat keyword, then kill my opponent's unit twice with it, how many cards does each player draw?

Ruling: You draw 0 cards total. Your opponent draws 2 cards total.

Sequence:

• First execution: Hidden Blade kills the targeted unit. The kill instruction executes successfully, so the linked draw instruction also executes - the unit's controller (your opponent) draws 2 cards.
• Second execution (Repeat): Hidden Blade attempts to kill the same unit again, but it's already dead. The kill instruction is ignored because there's no valid target.
• Because the kill instruction is ignored on the second execution, the linked draw instruction is also ignored. No one draws cards from the second execution.

Nuances:

• Hidden Blade uses linked instructions - the draw effect is linked to the kill effect that precedes it.
• When an earlier instruction in a linked chain is ignored (like trying to kill an already-dead unit), all later linked instructions are also ignored.
• Each execution of a Repeat effect is evaluated independently for whether its instructions execute or are ignored.