If opponent's Falling Star enters play targeting my Clockwork with 2 health and they have a Yordle on board, do they have to kill their own Yordle?

Ruling: No, the opponent can target your Clockwork twice with both damage triggers. One trigger will kill the Clockwork and the other will whiff (fail to resolve because the target is gone).

Sequence:

• When Falling Star resolves, 2 damage triggers go on the stack
• Both triggers must target valid units when placed on the stack
• The game doesn't account for whether a unit will die to one trigger when targeting
• If the Clockwork dies to the first trigger, the second trigger whiffs

Nuances:

• If you respond to Falling Star by removing your Clockwork (e.g., with Gust), then both triggers still need valid targets when they go on the stack, forcing the opponent to target their own Yordle