Cheapest priced copy (Aether Revolt): $0.35 at Card Kingdom, near mint, their price list as of .
Cruel Finality 
Instant · Common · Aether Revolt · #54
Target creature gets -2/-2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Aether Revolt | 54 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 9 February 2017If the target creature becomes an illegal target, Cruel Finality doesn’t resolve and none of its effects happen. You won’t scry 1.