Cheapest priced copy (Duskmourn: House of Horror): $0.35 at Card Kingdom, near mint, their price list as of .
Impossible Inferno 
Instant · Common · Duskmourn: House of Horror · #140
Impossible Inferno deals 6 damage to target creature.
Delirium — If there are four or more card types among cards in your graveyard, exile the top card of your library. You may play it until the end of your next turn.
Legal inCommanderBrawlStandardPioneerModernLegacyVintagePauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duskmourn: House of Horror | 140 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 20 September 2024You pay all costs and follow all timing rules for cards played this way. For example, if the exiled card is a land card, you may play it only during your main phase while the stack is empty.