Gather Courage is a uncommon Instant card from Magic 2015 (M15), collector number 175. Current market price: $0.10 (foil $0.40), 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.) Target creature gets +2/+2 until end of turn.