Boros Swiftblade, from Ravnica and Planechase (shown here):
Original Flavor Text: When the Boros Legion attacks, swiftblades enter the fray first. They pick off the archers and mages, softening the enemy front before the flame-kin and giants go in.
MtR Rewording: When the Boros Legion attacks, swiftblades enter the fray first. They make quick work of lightly armored troops, softening the enemy front before the flame-kin and giants go in.
This one is a bit of a nitpick. The flavor text bothers me because it doesn't really make sense - if your archers and mages are being picked off by guys with swords and shields, you might be a terrible military commander. Shouldn't they be stationed far back and not on the "enemy front"? I'd imagine that these guys would have to get through centaurs, mutants, weirds, and hordes of goblins before they could get to their targets. Also, wouldn't it be silly to have ground troops engage ranged support when you have skyknights and angels at your disposal?
I decided to just make a minor amendment to this one to retain the basic concept, but chose to be deliberately vague for the sake of logic. "Lightly armored troops" could refer to said archers and mages still, but also half naked Gruul barbarians or tentacled Simic experiments. This makes a hell of a lot more sense, as they would eliminate the rabble, but fall back as the bigger second wave enemies come in, letting the giants and flame-kin engage them.