Conclave Phalanx is a uncommon Creature — Human Soldier card from Duel Decks: Elspeth vs. Tezzeret (DDF), collector number 16. Current market price: $0.13, TCGplayer market prices via Scryfall.
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) When this creature enters, you gain 1 life for each creature you control.