Cheapest priced copy (Foundations Jumpstart): $0.59 at Card Kingdom, near mint, their price list as of .
Unleash Fury 
Instant · Uncommon · Core Set 2021 · #170
Double the power of target creature until end of turn.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.59 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Foundations Jumpstart | 608 | Uncommon | $0.59 | — |
| Core Set 2021 | 170 | Uncommon | $0.69 | $1.49 |
| Starter Commander Decks | 166 | Uncommon | $0.69 | — |
| Secret Lair Drop | 7050 | Rare | $2.79 | $3.49 |
One ruling from Wizards of the Coast
- 23 June 2020If an effect instructs you to "double" a creature's power, that creature gets +X/+0, where X is its power as that effect begins to apply. If its power is negative, instead it gets -X/-0 where X is how far below 0 its power is. The value of X won't change if another effect alters the creature's power later in the turn.