Cheapest priced copy (Duel Decks: Heroes vs. Monsters): $0.49 at Card Kingdom, near mint, their price list as of .
Nobilis of War 
Creature — Spirit Avatar · 3/4 · Rare · Eventide · #144
Flying
Attacking creatures you control get +2/+0.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.49 to $6.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Heroes vs. Monsters | 15 | Rare | $0.49 | — |
| Eventide | 144 | Rare | $0.59 | $6.99 |
| Modern Masters 2015 | 195 | Rare | $0.49 | $0.49 |
One ruling from Wizards of the Coast
- 1 August 2008This is a static ability. Attacking creatures you control will get +2/+0 from the moment they're declared as attackers (or enter attacking) until the moment the combat phase ends, they're removed from combat, or Nobilis of War leaves the battlefield, whichever comes first.