Setessan Tactics is a rare Instant card from Journey into Nyx (JOU), collector number 140. Current market price: $0.97 (foil $2.00), TCGplayer market prices via Scryfall.
Strive — This spell costs {G} more to cast for each target beyond the first. Until end of turn, any number of target creatures each get +1/+1 and gain "{T}: This creature fights another target creature."