You get 8 Set Booster packs, 4 Traditional Foil alternate-art cards, 40 Land cards (including 20 foils), plus a spindown life counter, a card storage box, and two reference cards
Disrupting an opponents board after they spend mana but before you untap will give you free reign to cast spells and attack while their defenses are down
Knights have been around in Magic: The Gathering since its inception, going all the way back to Alpha with Black Knight and White Knight
There are also limited time missions to complete that rewarded you with Wonder Hourglasses for completing Wonder Picks and collecting Psychic type cards, and a new Mew ex Circles Flair: Light blue (battle) that can be purchased for your duplicate cards
The time of year the likes of Gengar, Dusknoir, and others come out to play