Aethertow is a common Instant card from Modern Masters 2017 (MM3), collector number 205. Current market price: $0.10 (foil $0.07), TCGplayer market prices via Scryfall.
Put target attacking or blocking creature on top of its owner's library. Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)