If Imperial Decree is active and combat damage kills a unit, does it kill the unit twice, breaking through Zhonya's protection?

Ruling: Yes, Imperial Decree will kill the unit even after Zhonya's saves it from combat damage. The unit dies twice - once from combat damage (prevented by Zhonya's) and once from Imperial Decree's delayed trigger.

Sequence:

• Combat damage is dealt between equal might units
• Imperial Decree's delayed trigger is added as pending
• Immediate cleanup occurs: damaged units are killed and Imperial Decree's trigger is finalized
• Zhonya's replaces the death from combat damage and is removed from the board
• Imperial Decree's trigger resolves and kills the unit again

Nuances:

• The damage is only relevant for adding Imperial Decree's effect to the chain; when the effect resolves, it simply kills the unit regardless of current damage state
• It doesn't matter whether Zhonya's was hidden or already revealed before the combat