Trade Tokens have been replaced by Shinedust which can be obtained much more easily
6) Mewtwo ex Mewtwo ex can be a devastating attacker if you draw the cards to set it up quickly
What's not to like about an enchantment that can stop attackers, save your blockers, make your creatures invulnerable to removal, give you free morphing, and allow recursion of comes-into-play abilities -- for free
Not only is it a 7/7 that you can play at instant speed for the low cost of a Snake, but it also lets you untap your entire board to cast more things
Most games come down to creature beatdown to get the opponent to 0, and many creatures have effects that are far more powerful than just some stats
That's strong (if it ever happens), but not exactly game-winning enough to be worth the trouble of filling a deck with a bunch of 2-mana 3/1s