Cheapest priced copy (Foundations): $0.35 at Card Kingdom, near mint, their price list as of .
Heartfire Immolator 
Creature — Human Wizard · 2/2 · Uncommon · Foundations · #201
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{R}, Sacrifice this creature: It deals damage equal to its power to target creature or planeswalker.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Foundations | 201 | Uncommon | $0.35 | $0.49 |
| Core Set 2021 | 150 | Uncommon | $0.35 | $0.49 |
| Core Set 2021 | 396 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 23 June 2020Players can't take any actions between the time you begin to activate Heartfire Immolator's last ability and the time it's sacrificed. Notably, opponents can't try to lower its power.
- 23 June 2020Use Heartfire Immolator's power as it last existed on the battlefield to determine how much damage its last ability deals.