Sunblade Elf is a uncommon Creature — Elf Warrior card from Magic 2015 (M15), collector number 202. Current market price: $0.13 (foil $0.48), TCGplayer market prices via Scryfall.
This creature gets +1/+1 as long as you control a Plains. {4}{W}: Creatures you control get +1/+1 until end of turn.