Dawn's Light Archer

Flash on a green creature has always been priced as ambush insurance, and here the two keywords together do exactly one job: turning a fragile body into a surprise blocker that eats a flyer. A 4/2 will not survive most trades on the ground, but at instant speed with reach it exists to be held up, flashed in during the declare-attackers step, and used to answer an attacker the caster could not otherwise touch. The 2 toughness is the honest half of the deal: it lets the archer trade up in the air (four power off a green three-drop kills nearly any evasive creature its size), but it dies to the same combat math on the way back, so the card is a one-time roadblock rather than a repeatable wall. That is the whole tension of the design. Reach on a defensive green creature is old, but stapling flash to it moves the card off the durable-wall lineage (the Giant Spiders and Wall of Tanglecords that sit back all game) and onto a more tempo-minded axis, where the value is the information the opponent does not have. Green rarely gets to hold up mana for a threat; this is one of the small, disciplined places it does.