Cheapest priced copy (War of the Spark): $0.35 at Card Kingdom, near mint, their price list as of .
Storm the Citadel 
Sorcery · Uncommon · War of the Spark · #178
Until end of turn, creatures you control get +2/+2 and gain "Whenever this creature deals combat damage to a player or planeswalker, destroy target artifact or enchantment defending player controls."
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| War of the Spark | 178 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 3 May 2019Storm the Citadel affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won’t get +2/+2 or gain the triggered ability.
- 3 May 2019If a creature is attacking a planeswalker, the controller of the planeswalker is the defending player.