When every card you play bounces their creatures and spells back to their hand, the game is as good as won
Piglet can resist damage, and when you have no cards in hand, they can challenge ready characters
It means I left out some cool Convoke cards like Knight-Errant of Eos and cool untappers like Drumbellower, but I think the sacrifice is worth it
By the next set, Planar Chaos , there were already variations on this idea, and by Future Sight , the end of the Time Spiral block, you could see all kinds of Echo costs: red creatues could require you to pay black mana, cheap creatures to cast could end up being expensive later on, and Echo could even be something completely different than mana: Echo Discard a card. The possibilities that this little change opened up were incredible, and the Time Spiral block saw some really interesting Echo designs because of it