The card begs the oft-asked question, In the absence of an objective rule structure, do we all become Squee? The most obvious use of the card is to strengthen the waning popularity and power of U/R Storm in Modern (for a good list pre-Faithless Looting, see the list that I cited in my last article)
There are a ton of legendary creatures from this era that you could build decks around, though there are a lot of clunkers too
The end result is that in decks that are three or more colors, it's significantly harder to cut five or six lands and replace them with MDFCs while still having a mana base that is stable enough to avoid color screw and support your ramp
Only cards up to the Art Rare level, including diamond and 1-star cards, will be tradable at launch, with rarer cards like EX and gold cards excluded for now
Once per turn: You can target 1 monster your opponent controls with less ATK than this card