Cheapest priced copy (Theros Beyond Death): $0.69 at Card Kingdom, near mint, their price list as of .
Nylea's Intervention 
Sorcery · Rare · Theros Beyond Death Promos · #188p
Choose one —
• Search your library for up to X land cards, reveal them, put them into your hand, then shuffle.
• Nylea's Intervention deals twice X damage to each creature with flying.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.69 to $7.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Theros Beyond Death Promos | 188p | Rare | $2.99Out of stock | $7.99 |
| Theros Beyond Death Promos | 188s | Rare | — | $2.49 |
| Theros Beyond Death | 188 | Rare | $0.69 | $1.49 |
| Theros Beyond Death | 329 | Rare | $1.79 | $6.99 |
One ruling from Wizards of the Coast
- 24 January 2020The second mode of Nylea’s Intervention has it deal damage to each creature with flying equal to twice X. It doesn’t deal X damage to them then deal X damage again.