In the description for the polymorph spell it states:
The transformation lasts for the duration, or until the target drops to 0 hit points or dies.
When it reverts to its normal form, the creature returns to the number of hit points it had before it transformed. If it reverts as a result of dropping to 0 hit points, any excess damage carries over to its normal form.
When a polymorphed creature dies from power word kill, shouldn't it revert back to its normal form with its previous number of hit points?
How does the power word kill spell affect a creature with polymorph cast on it (whose new form has less than 100 HP)?