Winds of Rebuke
Tempo bounce has always paid for itself with a tax: Vapor Snag costs the controller a life, Unsummon does nothing but stall, and Boomerang charges to buy reach onto lands. The two-card mill clause here is a stranger rider, because it cuts both ways, and that symmetry is the whole design intent. Self-mill on a bounce spell reads as a downside on paper, yet it justifies the card's existence: in a graveyard-fueled shell, milling yourself two is upside, and returning a permanent while feeding your own yard turns a tempo play into a setup play. The mirror clause also grinds an opponent's library by two, incidental decking that only matters across a long enough game. Returning a nonland permanent at instant speed is the load-bearing flexibility: it answers a problematic creature mid-combat, resets an enters-the-battlefield trigger you control, saves a creature from a removal spell, or peels back an enchantment or planeswalker for a turn. What is usually a cost paid grudgingly becomes a resource the right shell actively wants, which is a rare thing to bolt onto an effect this cheap. The design reads as a bounce spell built for a self-mill deck first and a tempo deck second, and it behaves exactly that way.

