If a unit with 2 Zhonyas attached dies, do both Zhonyas get destroyed?

Ruling: No, you choose one of the Zhonyas to trigger. When 2 replacement effects happen on the same unit from the same source, you choose which one triggers.

Nuances:

• Guardian Angel has similar mechanics but its wording ("kill GA" rather than "kill a GA") creates ambiguity about whether you could kill a different GA on the board, though this interpretation is disputed and may not be intended.