Planeswalkers were introduced around the time of the release of Lorwyn and I immediately saw a potential for these cards. The first planeswalker that I liked was Garruk Wildspeaker. It untapped lands, generated elephant tokens and produced an Overrun effect. Planeswalkers are like creatures but harder to get rid of.
Out comes the Shards of Alara expansion and they Introduce the us Elspeth, Knight Errant. This card is a bit overpowered as it could replicate both an Angelic Blessing and a Kjeldoran Outpost. In a short span of time you could generate a ridiculous amount of soldier tokens to join your cause. The best part of this is that these effects are free with no mana cost. The ultimate power of Elspeth is making each and every artifact, creature, land and enchantment indestructible for the rest of the game.
I highly recommend this deck for with decks, Kithkin decks and control decks. I have personally used this card and racked up a good amount of victories in casual play. The price may be steep for a piece of cardboard but worth it.