Use +1/+1 counters to make your creatures bigger and stomp the opponent.
This deck is based on a single principle: use various +1/+1 counter adding spells and abilities to make your monsters strong enough to trample over your opponent. Hardened Scales and Winding Constrictor are the key pieces in your deck. A single extra +1/+1 counter may not seem like much at first glance, but all the cards are additive and make you really snowball with 2 of them in play.
There are several large bombs on several parts in your curve. Avatar of the Resolute only costs 2 mana and with is a trampling monster with at least 5 power, and reach is a great thing for most green decks. Walking Ballista is an overall great card that can bypass blockers, get rid of creatures without attacking them, or can just become huge and attack itself. Verdurous Gearhulk is a 8/8 creature with trample by itself, or can buff your other monsters with works great with any of your counter adding cards.
Kalonian Hydra
is a monster that is at least an 8/8 monster when it attack, but the doubling of your other counters is the main appeal and create some overwhelming boardstates. Your creatures may not have any innate protection, but Blossoming Defense and Inspiring Call make most removal spells fizzle out.
The deck is as midrange as they come, so some Fatal Pushes help you get in a better board position in the early game. There are not many decks that can get out bigger creatures, so you should be safe in the later stages of the game.
The deck originally had Gyre Sage in it, but after playing with it for a while I realized that I'm never really in a position where I'm short on mana and I'm able to put enough pressure on each turn without it. you also don't want a lot of two drops, and Winding Constrictor and Avatar of the Resolute are too valuable to drop. Rishkar, Peema Renegade is enough for this deck to ramp with.
Overall the deck is a joy to play with. your Counter adding cards are just nuts, and it always feels good to ram your opponent with a giant Hydra that ends the game in a single swing. Have fun trying it out and let me know what you think of it.
