Does Zhonya's errata allow the player to choose when to use the effect?

Ruling: No, you cannot choose when to use Zhonya's effect. It is a passive replacement effect that applies automatically, not a delayed trigger.

Nuances:

• If several units die at the same time, you can choose which one is affected
• The errata changed the wording from "next time" to clarify it functions as a passive replacement effect rather than a delayed trigger
• The errata also added heal and made other effects more precise