The level counters the card owns determine its power, toughness, and sometimes abilities
And if you're interested in more talk about brackets, you can check out today's update on those (including several new Game Changers) in this article
The Final Fantasy Bundle, containing nine Play Boosters, two traditional foil extended arts, 16 foil full-art basic lands, a spindown life counter, two reference cards, and a storage box is also available for preorder, as is the Starter Kit, which contains two precon decks for Standard play
For reference, here is Deaths Shadow before the banning of Gitaxian Probe and the list that Josh Utter-Leyton used to win the GP:The first thing you will notice is that the creature package is much tighter