Cheapest priced copy (Commander 2013 Oversized): $1.49 at Card Kingdom, foil, near mint, their price list as of .
The Sorceress, Heroic Guardian 
Derevi, Empyrial Tactician
Legendary Creature — Bird Wizard · 2/3 · Rare · Secret Lair Drop · #2787
Flying
When Derevi enters and whenever a creature you control deals combat damage to a player, you may tap or untap target permanent.
{1}{G}{W}{U}: Put Derevi onto the battlefield from the command zone.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
6 printings · $1.49 to $17.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Bloomburrow Commander | 87 | Rare | $14.99 | $17.99 |
| Commander 2013 | 186 | Mythic | $8.49 | — |
| Commander Anthology | 176 | Mythic | — | $8.99 |
| Commander Legends | 518 | Mythic | — | — |
| Commander 2013 Oversized | 186 | Mythic | — | $1.49 |
| Secret Lair Drop (The Sorceress, Heroic Guardian) | 2787 | Rare | $7.99 | $15.99 |
3 rulings from Wizards of the Coast
- 19 January 2015Derevi, Empyrial Tactician is banned as a commander in Duel Commander format, but it may be part of your deck.
- 10 November 2020You can activate Derevi's last ability only when it is in the command zone.
- 10 November 2020When you activate Derevi's last ability, you're not casting Derevi as a spell. The ability can't be countered by something that counters only spells. The ability isn't subject to the commander tax, nor does it increase the tax if you cast Derevi from the command zone later in the game.