Arcee, Sharpshooter is a 2/2 creature with first strike, and you can pay one generic mana to remove any number of +1/+1 counters from it to deal that much damage to a creature
In addition to this, a big part of the reason these cards were so popular was because the mana in that Standard format was quite bad, to the extent that you were pretty close to wanting Attune with Aether in your decks even before the energy bonus, but once you have the energy bonus you might as well play Harnessed Lightning, which means you may as well play Rogue Refiner to power up your kill spell, and so on
cards, these prize printings combine nostalgia with extreme scarcity
Also, this is notable for being the only flesh-and-blood gnome that MTG will have
You must target six different creatures
This is a perfect one to start on