Cheapest priced copy (Journey into Nyx): $0.35 at Card Kingdom, near mint, their price list as of .
War-Wing Siren 
Creature — Siren Soldier · 1/3 · Common · Journey into Nyx · #57
Flying
Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Journey into Nyx | 57 | Common | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 26 April 2014Heroic abilities will resolve before the spell that caused them to trigger.
- 26 April 2014Heroic abilities won't trigger when a copy of a spell is created on the stack or when a spell's targets are changed to include a creature with a heroic ability.
- 26 April 2014Heroic abilities will trigger only once per spell, even if that spell targets the creature with the heroic ability multiple times.