Cheapest priced copy (Double Masters 2022): $1.79 at Card Kingdom, near mint, their price list as of .
Legion's Initiative 
Enchantment · Mythic · Dragon's Maze · #81
Red creatures you control get +1/+0.
White creatures you control get +0/+1.
{R}{W}, Exile this enchantment: Exile all creatures you control. At the beginning of the next combat, return those cards to the battlefield under their owner's control and those creatures gain haste until end of turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $1.79 to $4.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters 2022 | 242 | Rare | $1.79 | $2.49 |
| Double Masters 2022 | 517 | Rare | — | — |
| Dragon's Maze | 81 | Mythic | $2.49 | $4.99 |
2 rulings from Wizards of the Coast
- 15 April 2013A creature that's both red and white will get +1/+1 from Legion's Initiative.
- 15 April 2013The beginning of the next combat will happen even if the player whose turn it is doesn't intend to attack with any creatures.