In my experience, packs have one common card of each of the six ink colors, and more cells let you separate cards of higher rarity by color as well
Simply type the name of the card using the double slash // "Expansion // Explosion"
Youre choosing speed over comfort, and the drawbacks come with it: the damage adds up, the untap cost is annoying, and if the game goes long it can feel clunky
Once it transforms, you get an emblem with its life drain ability, and now whenever it attacks, you may sacrifice any number of Creatures to draw that many cards instead of sacrificing them one at a time
It provides a win condition and stalls the game as you block your opponents creatures forever
Play With Fire This is just better Shock, not quite Lightning Bolt better, but still, Shock with upside is nothing to scoff at