Cheapest priced copy (Murders at Karlov Manor): $0.49 at Card Kingdom, near mint, their price list as of .
Niv-Mizzet, Guildpact 
Legendary Creature — Dragon Avatar · 6/6 · Rare · Murders at Karlov Manor · #368
Flying, hexproof from multicolored
Whenever Niv-Mizzet deals combat damage to a player, it deals X damage to any target, target player draws X cards, and you gain X life, where X is the number of different color pairs among permanents you control that are exactly two colors.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
6 printings · $0.49 to $4.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Murders at Karlov Manor | 220 | Rare | $0.49 | $0.99 |
| Murders at Karlov Manor | 319 | Rare | $0.69 | $4.49 |
| Murders at Karlov Manor | 319z | Rare | — | — |
| Murders at Karlov Manor | 368 | Rare | $0.69 | $1.49 |
| Murders at Karlov Manor Promos | 220p | Rare | $0.99 | $0.99 |
| Murders at Karlov Manor Promos | 220s | Rare | — | $1.29 |
2 rulings from Wizards of the Coast
- 2 February 2024The value of X is checked only once, as Niv-Mizzet, Guildpact's triggered ability resolves.
- 2 February 2024A "color pair" is exactly two colors. There are ten color pairs in Magic: white-blue, white-black, blue-black, blue-red, black-red, black-green, red-green, red-white, green-white, and green-blue.