Cheapest priced copy (Assassin's Creed): $0.35 at Card Kingdom, near mint, their price list as of .
Origin of the Hidden Ones 
Enchantment — Saga · Uncommon · Assassin's Creed · #36
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga deals 4 damage to any target.
II — Create two 1/1 black Assassin creature tokens with menace.
III — Whenever an Assassin you control attacks this turn, create a 1/1 black Assassin creature token with menace that's tapped and attacking.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Assassin's Creed | 36 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 5 July 2024You choose which player, planeswalker, or battle the Assassin tokens are attacking. Each Assassin token can enter attacking a different player, planeswalker, or battle, and they don't need to be the same ones that the Assassins you control are attacking.
- 5 July 2024Although the tokens created by the third chapter ability enter the battlefield attacking, they were never declared as attacking creatures. Abilities that trigger whenever a creature attacks won't trigger when they enter the battlefield attacking.