Cheapest priced copy (Innistrad: Double Feature): $0.35 at Card Kingdom, near mint, their price list as of .
Necrosynthesis 
Enchantment — Aura · Uncommon · Innistrad: Double Feature · #115
Enchant creature
Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature."
When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Innistrad: Double Feature | 115 | Uncommon | $0.35 | $3.49 |
| Innistrad: Midnight Hunt | 115 | Uncommon | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 24 September 2021Use the enchanted creature's power as it last existed on the battlefield to determine the value of X.