When Kai'Sa's signature spell (Icathian Rain) targets units and the opponent plays Zhonya's Hourglass in response, does the spell generate multiple cleanup steps between repetitions, does Zhonya's prevent all damage or just the last repetition, and can you bypass Zhonya's by assigning additional repetitions to the same unit?

Ruling: A cleanup only occurs once Icathian Rain has fully finished resolving, not between repetitions. When Zhonya's Hourglass prevents a unit from dying, all damage on that unit should be removed (rules-as-intended), so you cannot "double-kill" a unit by applying extra damage with additional repetitions of Icathian Rain.

Sequence:

• Icathian Rain resolves completely with all repetitions
• Only after the spell fully resolves does cleanup occur
• If Zhonya's triggers during cleanup, all damage is removed from the saved unit

Nuances:

• This interaction involves a known issue where the Core Rules do not currently state that damage should be removed when Zhonya's prevents death, but rules-as-intended clarify that all damage is removed