Guardians of Oboro is a common Creature — Moonfolk Samurai card from Kamigawa: Neon Dynasty (NEO), collector number 317. Current market price: $0.10 (foil $0.23), TCGplayer market prices via Scryfall.
Defender Modified creatures you control can attack as though they didn't have defender. (Equipment, Auras you control, and counters are modifications.)