Cheapest priced copy (Bloomburrow): $0.39 at Card Kingdom, near mint, their price list as of .
Heartfire Hero 
Creature — Mouse Soldier · 1/1 · Uncommon · Bloomburrow · #138
Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it.
When this creature dies, it deals damage equal to its power to each opponent.
Legal inCommanderBrawlModernLegacyVintage
Banned inStandardPioneer
Not legal inPauper
1 printing · $0.39 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Bloomburrow | 138 | Uncommon | $0.39 | $0.49 |
4 rulings from Wizards of the Coast
- 26 July 2024Use Heartfire Hero's power as it last existed on the battlefield to determine how much damage it deals due to its last ability.
- 26 July 2024If a spell or ability you control has one or more of its targets changed to a creature you control with a valiant ability, that ability will trigger if that creature hasn't yet been the target of a spell or ability you control this turn.
- 26 July 2024If you create a copy of a spell on the stack and target a creature you control with a valiant ability, that ability will trigger as long as the creature hasn't yet been the target of a spell or ability you control this turn.
- 26 July 2024Valiant abilities will resolve before the spell or ability that caused them to trigger.