Enchantment
When this enchantment enters, create a Blood token for each opponent you have. (It's an artifact with "

,

, Discard a card, Sacrifice this token: Draw a card.")
Blood tokens you control are Equipment in addition to their other types and have "Equipped creature gets +2/+0" and equip

.
If a Blood token is somehow both a creature and an Equipment, it can't be attached to a creature.
If you control more than one Arterial Alchemy, creatures equipped with Blood Equipment will get +2/+0 for each Arterial Alchemy. The equip cost is still
.
Blood tokens stop being Equipment if Arterial Alchemy leaves the battlefield. If any of them are attached to creatures at that time, they become unattached.
You can't sacrifice a Blood token to pay multiple costs.
If an effect refers to a Blood token, it means any artifact token with the subtype Blood, even if it has gained other subtypes.
Some triggered abilities trigger "whenever you sacrifice a Blood token." These abilities trigger regardless of why you sacrificed that Blood token.