The Elder Dragon War is a rare Enchantment — Saga card from Foundations Commander (FDC), collector number 156. Current market price: $0.27, TCGplayer market prices via Scryfall.
Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.) I — This Saga deals 2 damage to each creature and each opponent. II — Discard any number of cards, then draw that many cards. III — Create a 4/4 red Dragon creature token with flying.