Cheapest priced copy (Duel Decks: Speed vs. Cunning): $0.35 at Card Kingdom, near mint, their price list as of .
Mardu Heart-Piercer 
Creature — Human Archer · 2/3 · Uncommon · Khans of Tarkir · #116
Raid — When this creature enters, if you attacked this turn, this creature deals 2 damage to any target.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Speed vs. Cunning | 13 | Uncommon | $0.35 | — |
| Jumpstart 2022 | 572 | Uncommon | $0.35 | — |
| Khans of Tarkir | 116 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 8 November 2024Raid abilities evaluate the entire turn to see if you attacked with a creature. That creature doesn't have to still be on the battlefield. Similarly, the player, planeswalker, or battle it attacked doesn't have to still be in the game or on the battlefield.
- 8 November 2024Raid abilities care only that you attacked with a creature. It doesn't matter how many creatures you attacked with or which player, planeswalker, or battle those creatures attacked.