Cheapest priced copy (Magic 2012): $0.35 at Card Kingdom, near mint, their price list as of .
Dark Favor 
Enchantment — Aura · Common · Magic 2013 · #86
Enchant creature
When this Aura enters, you lose 1 life.
Enchanted creature gets +3/+1.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic 2012 | 89 | Common | $0.35 | $0.49 |
| Magic 2013 | 86 | Common | $0.35 | $0.49 |
| Magic 2014 | 92 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 22 September 2011If the creature targeted by Dark Favor is an illegal target when Dark Favor tries to resolve, Dark Favor won't resolve. It won't enter and its "enters" ability won't trigger.