Assemble the Legion is a rare Enchantment card from The List (PLST), collector number GTC-142. Current market price: $0.33, TCGplayer market prices via Scryfall.
At the beginning of your upkeep, put a muster counter on this enchantment. Then create a 1/1 red and white Soldier creature token with haste for each muster counter on this enchantment.