Echoes of Eternity is a rare Kindred Enchantment — Eldrazi card from Modern Horizons 3 Promos (PMH3), collector number 4p. Current market price: $2.17 (foil $2.08), 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.)