Does Mystic Reversal allow you to target any spell on the chain or only the one directly before it, and does the player who uses Mystic Reversal count as having 'played' the controlled spell for trigger purposes?

Ruling: Mystic Reversal can target any spell currently on the chain, not just the one directly before it. The player who uses Mystic Reversal becomes the controller of the spell and counts as having played it when it resolves, triggering effects like Ravenbloom Student.

Sequence:

• Mystic Reversal resolves first, giving +1 to Ravenbloom Student
• Opponent gets priority
• The reversed spell resolves, giving another +1 to Ravenbloom Student

Nuances:

• While Mystic Reversal is generally played to target the spell directly before it on the chain, it can legally target any spell currently on the chain
• A spell isn't considered 'played' until it resolves, which is why the controller (not the owner) is the one who counts as playing it