FOILCheapest priced copy (Magic Origins): $0.49 at Card Kingdom, near mint, their price list as of .
Gideon's Phalanx 
Instant · Rare · Magic Origins Promos · #14s
Create four 2/2 white Knight creature tokens with vigilance.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, creatures you control gain indestructible until end of turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.49 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic Origins | 14 | Rare | $0.49 | $0.99 |
| Magic Origins Promos | 14s | Rare | — | $0.69 |
2 rulings from Wizards of the Coast
- 22 June 2015Check to see if there are two or more instant and/or sorcery cards in your graveyard as the spell resolves to determine whether the spell mastery ability applies. The spell itself won’t count because it’s still on the stack as you make this check.
- 22 June 2015If the spell mastery ability applies, the four Knight tokens will also gain indestructible until end of turn.