Drawing cards is vital in Magic, and with Gix in play, whenever a creature you control deals damage to an opponent, you can choose to draw a card and lose a life for each creature
Legends has it that WotC was worried Snapcaster Mage/Delver of Secrets decks would be too powerful in the metagame so Cavern of Souls was printed to help defend against the blue menace
Source: WotC WPN Collector Booster boxes (also called Displays) are just a way to buy 12 Collector Boosters together
This years holiday-themed card is Naughty/Nice
One attack can be chosen from this attack card as long as the correct amount and type of energy is attached to this card, with this energy not being discarded unless specified
Either way, you want your general to be devastating if left unchecked Engines synergy focused decks look to their commanders to tie the room together, making cards more than the sum of their parts that harmonise into something much bigger