Cheapest priced copy (Rivals of Ixalan): $0.59 at Card Kingdom, near mint, their price list as of .
Arterial Flow 
Sorcery · Uncommon · Rivals of Ixalan · #62
Each opponent discards two cards. If you control a Vampire, each opponent loses 2 life and you gain 2 life.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.59 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Rivals of Ixalan | 62 | Uncommon | $0.59 | $3.99 |
3 rulings from Wizards of the Coast
- 19 January 2018In a Two-Headed Giant game, Arterial Flow causes the opposing team to lose 4 life, and each player on that team discards two cards. You gain 2 life.
- 19 January 2018Arterial Flow causes each opponent to lose 2 life if you control a Vampire, even if some or all of those players were unable to discard any cards.
- 19 January 2018Whether you control a Vampire is checked as Arterial Flow resolves.