I am SO sick of everyone saying scyther's swords dance is a waste of time! It is specifically designed to let you attack for extra damage in your first few turns of the game. Scenario 1: your hand is a grass energy and a double colorless. You attach the grass and do swords dance. On your next turn, you stick on the DCE and do slash for 60. You wouldn't normally be able to do that kind of damage with scyther so early. Scenario 2: your hand is 3 grass energies. stick a grass on scyther and swords dance. On your next turn, repeat the process. On the third turn, slash and end up doing 60 damage, essentially doing 60 for 3 energy! If you can't understand what I'm talking about, take all the scythers out of your deck because you'll never be able to use it as the fast early game attacker it is.

 

P.S. no hate mail, please!