Their best use is as the only legendary creature with banding, so that allows you to laboriously explain those rules to new players, effectively stifling their love of Magic before it can even kindle
I might be able to see this perspective if the only counterfeiting problem involved dual lands, Power Nine cards, and other absurdly expensive, unreprintable Reserved List cards, but the demand for counterfeit Standard cards, $15 Commander cards, and Pauper staples works against the argument that the fake card problem is just about $600 Underground Seas and $2,500 The Tabernacle at Pendrell Vales
While you could certainly just play Krrik fair as one of the 99 in a mono-black deck as a way to occasionally cast spells ahead of time, this legend shines in a deck built to truly abuse it
Rare Card
Infinite combos and Stax are far from the only ways to make a Derevi flicker deck dangerous, however