Echoes of Eternity is a rare Kindred Enchantment — Eldrazi card from Modern Horizons 3 (MH3), collector number 320. Current market price: $3.78 (foil $8.23), TCGplayer market prices via Scryfall.
If a triggered ability of a colorless spell you control or another colorless permanent you control triggers, that ability triggers an additional time. Whenever you cast a colorless spell, copy it. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)