Do replacement effects like Sett and Zhonya use the stack/chain, and how do they work when multiple units are dying simultaneously?

Ruling: Replacement effects like Sett and Zhonya do not use the chain. They replace the core game mechanic of an object dying with what their card says to do instead.

Sequence: (when multiple units are dying simultaneously)

• Active player chooses first whether to use their replacement effect
• Non-active player then makes their choice

Nuances:

• When something would die, the player confirms if they want to use the replacement effect (Zhonya is automatic, Sett involves a choice)