HIGH-QUALITY COMPONENTS: Contains 1 starter deck of 60 cards (including 2 foil cards), 11 damage counters, 1 paper playmat, 1 paper tracker token, 1 Quick Start Rules sheet, and 1 BONUS booster pack of 12 randomized cards
In metagames rife with Reliquary Towers and full grips, this is going to be obscenely good (because it'll be like a 30/30, and it will tutor for that Strip Mine, Dust Bowl, and/or Wasteland to destroy the Towers)
(Even the TMNT set's sole pre-constructed Commander deck is built around +1/+1 counters.) If you're currently trying to buy a copy of Doubling Season on the second-hand market, you'll probably wind up spending around $30 (depending on the art, card condition, and seller)
Grixis Shadow
It gets the preference here over Arachnogenesis because elves are a much more well-supported deck than spiders, and you can certainly play both in your green tokens deck