Thanks to cards like instants, you can react to anything your opponent does: counter their spells, destroy their creatures, or deal the last few points of damage necessary to win the game
By exiling cards from your graveyard, you can cast Dig Through Time for as little as two mana
Kalonian Hydra, Sovereign Okinec Ahau, Innkeeper's Talent, and Maester Seymour all help us rapidly scale up our board with +1/+1 counters
A quick evolution to Gyrados from Magikarp with a very lucky Misty Supporter Card coin flip, might grant you one shot early in the game and stall the energy gathering of your psychic opponent, but chances are that by the time you've evolved and energized your big hitter enough to try a Hyper Beam, you've already been Psydrived for your full 150 HP
The Green one is my fave
For each opponent who cant, you draw a card