Hydra tribal, not an original way to build a deck but a strong way. Every hydra can and likely will be swinging for lethal in this deck focused on turbo buffing the number of +1/+1 counters you have through exponential growth.
Key Players:
Doubling Season, Primal Vigor, The Ozolith, Unbound Flourishing, Branching Evolution, Vorinclex, Monstrous Raider
Being mono-green there are few responses to board wipes available, so what if instead we made board wipes make us win? Enter The Ozolith. Creature destruction no longer matters as all your +1/+1 counters are safe and sound ready to be put back onto the next creature you pull out. As if that was not good enough, Doubling Season triggers when counters move to The Ozolith and when you move them onto creatures as you enter combat. Primal Vigor and Branching Evolution trigger when moving from The Ozolith, meaning that if you lose all creatures one turn by your very next combat phase you could have a creature with 2^4 (doubled 4 times) the number of +1/+1 counters you had before the wipe.
For example if you barely had any power out before the wipe and only had 3 +1/+1 counters between your creatures, they would double moving to The Ozolith (6), then on your next turn you play a creature (the NUT play would be Vorinclex, Monstrous Raider) and move to the combat phase, Doubling Season, Primal Vigor, and Branching Evolution all trigger taking your 3 original counters up to 48 and you are suddenly swinging for lethal against open boards. If the creature is Vorinclex the 3 counters become 98, oh and it has Haste. Exponential growth is ridiculous.
Obviously that is perfect conditions, but with all of the ways in this deck to create massive Hydras you will have more than enough damage all game.
Heroes' Bane + Selvala, Heart of the Wilds
is excessively powerful. Selvala turns power into mana and Heroes' Bane turns 4 mana into an additional doubling of power, combined with Overwhelming Stampede all your creatures can be swinging for literally trillions of damage each (4 * 2^38 is over a trillion, with all the doubling effects triggering each time Heroes' Bane is activated 38 doubles is quite doable). Exponents too strong.
Other notable interactions:
-When casting Astral Cornucopia, Unbound Flourishing doubles the value of X, Doubling Season and Vorinclex, Monstrous Raider double the counters put on Astral Cornucopia on cast, and Cornucopia's counters can also be proliferated by Evolution Sage's landfall trigger as well as Karn's Bastion.
-With Emerald Medallion, Herald's Horn, and Urza's Incubator hydras cost 5 less to cast, combined with Gargos, Vicious Watcher X cost hydras come out +9/+9 bigger.
-Kalonian Hydra is extremely good in this deck as its ability adds yet another degree of power to the exponential growth of all your creatures.
-Solidarity of Heroes can target more than one of your creatures, which will activate Gargos, Vicious Watcher each time to fight enemy creatures.
-Nature's Way and Rabid Bite trigger Gargos and can allow you to destroy an enemy's board full of Flying creatures before even going to combat.
New to MtG and deck building, so I would love feedback letting me know what I missed. What weaknesses does this deck have? It there something that should be replaced for something better I don't know about yet?
