If Charm is used to send Qiyana to another battlefield where she dies, can Zhonya's be used in reaction to save her, and where does Zhonya's go when played?

Ruling: Zhonya's is a gear card that must be placed in base, not on a battlefield. When you respond to Charm by playing Zhonya's from hidden, it goes to base and can save your champion.

Sequence:

• Charm is used on Qiyana to send her to another battlefield
• You can respond by revealing/playing Zhonya's from hidden
• Zhonya's goes to base (not the battlefield)
• Because Zhonya's is not targeted and is in base, it can affect your champion

Nuances:

• You can hide Zhonya's on a battlefield, but when you reveal/play it, it must go to base
• When played for its usual cost, Zhonya's always comes to base
• Revealing it from hidden counts as playing it, which is why it goes to base and can affect everything