Cheapest priced copy (Duel Decks: Divine vs. Demonic): $0.99 at Card Kingdom, near mint, their price list as of .
Promise of Power 
Sorcery · Rare · Mirrodin · #74
Choose one —
• You draw five cards and you lose 5 life.
• Create an X/X black Demon creature token with flying, where X is the number of cards in your hand.
Entwine {4} (Choose both if you pay the entwine cost.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
5 printings · $0.99 to $2.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2014 | 157 | Rare | $1.29 | — |
| Duel Decks: Divine vs. Demonic | 54 | Rare | $0.99 | — |
| Duel Decks Anthology: Divine vs. Demonic | 54 | Rare | $0.99 | — |
| Mirrodin | 74 | Rare | $0.99 | $2.99 |
| The List | DDC-54 | Rare | $1.29 | — |
3 rulings from Wizards of the Coast
- 4 October 2004The power/toughness of the token is set when this spell resolves.
- 1 December 2004The power and toughness of the Demon token are set when Promise of Power resolves. They’re unaffected if the number of cards in your hand changes later.
- 1 December 2004If you pay the entwine cost, you draw five cards, then lose five life, then put the Demon token onto the battlefield. The five cards you draw count toward the Demon’s power and toughness.