The basic idea is ramp into huge creatures, utilising Kruphix, God of Horizons +
Prophet of Kruphix
to get a ton of mana up for either Genesis Hydra or to Monstrous Hydra Broodmaster
Mainboard:
Arbor Colossus
: a 6/6 for 5 mana and triple green devotion? Yes please, also deals with pesky flying bastards like Stormbreath Dragon, Archangel of Thune and Desecration Demon
Archetype of Endurance
: 8 Mana for a 6/5 is kinda pricey, but his effect is what saves me most games, stops any deck with black, dead in it's tracks, amazing.
Chord of Calling: Instant speed creature tutor onto the battlefield, need I say more?
Courser of Kruphix: Mana Acceleration, Deck Thining, 2/4 for 3 mana, awesome.
Genesis Hydra: Pure awesome, with the amount of mana I can produce, this creature gets me almost anything I want and gives me a big-ass hydra in the process.
Hornet Queen: Triple green devotion so works wonders with Acolyte and Nykthos, also provides me with lovely little flying deathtouch defenders.
Hornet Nest: Combo with Setessan tactics and some of your huge creatures to produce a ghastly amount of tokens
[[Hydra Broodmaster: I. Love. This. Card. 6 Mana for a 7/7. Yum. Throw in big-ass hydra babies and you have a real winner. (FYI My record is 64 64/64 Hydra Tokens)
Karametra's Acolyte: Creature version of Nykthos, Shrine to Nyx, a true champ
Kiora's Follower: Untaps Stuff, great synergy with Karametra's Acolyte and Nykthos, Shrine to Nyx.
Kruphix, God of Horizons: No max hand size, Infinite mana, he is the enabler for this deck.
Polukranos, World Eater: 4 mana 5/5 with a removal monstrous ability that can get truly huge.
Prophet of Kruphix
: Flash Creatures in opponents end step gives big monsters Pseudo-Haste and allowing to untap with my opponent provides even more mana with Kruphix, God of Horizons.
Setessan Tactics: Removal with Strive, my big-ass creatures fight your little weenie bitches, no more blockers.
Soul of New Phyrexia: 6 mana for a 6/6 with trample, yes, then he gives all my stuff indestructible, and with the mana I can produce it isn't a problem. Anti Control.
Sylvan Caryatid: 0/3 Hexproof Mana Producer for 2 mana, yay :D
Thassa, God of the Sea don't need her as a creature, scry before draw is awesome and being able to make my huge creatures unblockable is a true champ ability
Sideboard:
Mistcutter Hydra: Anti Blue
AEtherspouts: Perfect for swinging with all, and watching your opponent swing back, thinking he's killed you, only to find all of his creatures gone, also slows down opponents draws. Side in against more aggressive decks
Back to Nature: Side in vs. Banishing Light and Detention Sphere
Bow of Nylea: Side in against aggro for life gain
Nylea's Disciple
: See above
Soul of Zendikar: If I need more creatures
Soul of New Phyrexia: Side in against control for more indestructible
Terra Stomper
: Anti Control
Archetype of Endurance
: If I come up against removal heavy decks.
