The dates for the preview season have yet to be announced
While supplies last, you can receive a traditional foil, extended-art Lifecraft Engine Buy-a-Box promo when you purchase a Play Booster box or Collector Booster box from your local game store, so contact them for details
Right now, these are retailing between $2 (Mountain and Plains) and $4 (Island)
Your colorless utility lands include Karn's Bastion for bonus proliferation, Mirrex for additional Phyrexian Mite token creation, and Inkmoth Nexus as a sneaky infecting creature land
Basically you load up on your favorite High CMC spells - Eldrazi Titans (Ulamog, the Infinite Gyre), extravagant board wipes (Decree of Annihilation), whatever you find interesting (Myojin of Night's Reach) and just go to town
In an aggressive deck, this is likely to be more than enough to kill them off - and that's not accounting for any extra creatures you may have, any ramping you've done or spare mana you've created