Cheapest priced copy (Secret Lair Drop): $2.99 at Card Kingdom, near mint, out of stock, their price list as of .
Kaya, Ghost Assassin 
Legendary Planeswalker — Kaya · Mythic · Secret Lair Drop · #247
0: Exile Kaya or up to one target creature. Return that card to the battlefield under its owner's control at the beginning of your next upkeep. You lose 2 life.
−1: Each opponent loses 2 life and you gain 2 life.
−2: Each opponent discards a card and you draw a card.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $2.99 to $34.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Conspiracy: Take the Crown | 75 | Mythic | $4.49 | — |
| Conspiracy: Take the Crown | 222 | Mythic | — | $34.99 |
| The List | CN2-75 | Mythic | $5.49 | — |
| Secret Lair Drop | 247 | Mythic | $2.99Out of stock | $2.99 |
3 rulings from Wizards of the Coast
- 23 August 2016As the last ability resolves, each opponent will choose a card to discard and set it aside. Then all those cards are revealed and discarded simultaneously.
- 23 August 2016You choose whether or not to target a creature as you activate the first ability. If you chose a target creature, you choose whether to exile Kaya or that creature as the ability resolves. If you chose a creature and that creature is no longer a legal target as the ability tries to resolve, the ability doesn't resolve and none of its effects happen. You won't exile Kaya or lose 2 life.
- 23 August 2016If you didn't choose a target creature for the first ability, and Kaya isn't on the battlefield as the ability resolves, you'll just lose 2 life. No card will be exiled or returned to the battlefield.