Cheapest priced copy (Archenemy): $0.49 at Card Kingdom, near mint, their price list as of .
Extractor Demon 
Creature — Demon · 5/5 · Rare · Conflux · #44
Flying
Whenever another creature leaves the battlefield, you may have target player mill two cards.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
7 printings · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Archenemy | 15 | Rare | $0.49 | — |
| Commander 2015 | 124 | Rare | $0.49 | — |
| Commander Anthology Volume II | 62 | Rare | $0.49 | — |
| Commander Anthology | 59 | Rare | $0.49 | — |
| Commander 2011 | 81 | Rare | $0.49 | — |
| Conflux | 44 | Rare | $0.49 | $0.49 |
| Modern Masters 2017 | 69 | Rare | $0.49 | $0.49 |
2 rulings from Wizards of the Coast
- 14 March 2017You can target any player with Extractor Demon’s triggered ability. The target doesn’t have to be the controller of the creature that left the battlefield.
- 14 March 2017If Extractor Demon and another creature leave the battlefield at the same time, Extractor Demon’s triggered ability will trigger.