Myr Matrix is a rare Artifact card from Darksteel (DST), collector number 132. Current market price: $9.23 (foil $24.14), TCGplayer market prices via Scryfall.
Indestructible (Effects that say "destroy" don't destroy this artifact.) Myr creatures get +1/+1. {5}: Create a 1/1 colorless Myr artifact creature token.