Cheapest priced copy (Duel Decks: Venser vs. Koth): $0.49 at Card Kingdom, near mint, their price list as of .
Windreaver 
Creature — Elemental · 1/3 · Rare · Dissension · #138
Flying
{W}: This creature gains vigilance until end of turn.
{W}: This creature gets +0/+1 until end of turn.
{U}: Switch this creature's power and toughness until end of turn.
{U}: Return this creature to its owner's hand.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.49 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duel Decks: Venser vs. Koth | 19 | Rare | $0.49 | — |
| Dissension | 138 | Rare | $0.49 | $3.49 |
| RNA Guild Kit | 22 | Rare | $0.49 | — |
3 rulings from Wizards of the Coast
- 19 March 2021Switching a creature's power and toughness twice (or any even number of times) effectively returns the creature to the power and toughness it had before any switches.
- 19 March 2021Effects that switch a creature's power and toughness apply after all other effects, regardless of when those effects began to apply. For instance, if you target a 1/2 creature then give it +2/+0 later in the turn, it's a 2/3 creature, not a 4/1 creature.
- 19 March 2021Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a creature may become lethal if you switch its power and toughness during that turn.