Netherborn Phalanx is a uncommon Creature — Horror card from GRN Guild Kit (GK1), collector number 6. Current market price: $0.34, TCGplayer market prices via Scryfall.
When this creature enters, each opponent loses 1 life for each creature they control. Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)