Cheapest priced copy (Seventh Edition): $9.49 at Card Kingdom, near mint, their price list as of .
Tainted Aether 
Enchantment · Rare · Seventh Edition · #167
Whenever a creature enters, its controller sacrifices a creature or land of their choice.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
3 printings · $9.49 to $139.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Seventh Edition | 167 | Rare | $9.49 | — |
| Seventh Edition | 167★ | Rare | — | $139.99Out of stock |
| Urza's Saga | 161 | Rare | $10.99 | — |
4 rulings from Wizards of the Coast
- 4 October 2004If more than one of these is on the battlefield, the controller sacrifices a creature for each one of these.
- 4 October 2004If the controller has no other lands or creatures on the battlefield, they must sacrifice the creature that just entered.
- 4 October 2004Tainted Aether's controller is the one that controls its triggered ability, but the controller of the creature that entered chooses what creature they sacrifice during resolution.
- 4 October 2004If the creature changes controllers before this ability resolves, its new controller has to sacrifice something.