Cheapest priced copy (Oath of the Gatewatch): $0.35 at Card Kingdom, near mint, their price list as of .
Flaying Tendrils 
Sorcery · Uncommon · Oath of the Gatewatch · #70
Devoid (This card has no color.)
All creatures get -2/-2 until end of turn. If a creature would die this turn, exile it instead.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Friday Night Magic 2016 | 9 | Rare | — | $0.49 |
| Oath of the Gatewatch | 70 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 22 January 2016Only creatures that are on the battlefield as Flaying Tendrils resolves will get -2/-2. However, any creature that would die that turn will be exiled, even if it wasn’t on the battlefield or wasn’t a creature as Flaying Tendrils resolved.
- 22 January 2016Creatures that Flaying Tendrils would cause to die will be exiled instead. The game doesn’t check to see which creatures die until after Flaying Tendrils has finished resolving.