Plus +1 good deck ramp. i see its somewhat inspired by mine. Looks really good.as of advice, i would say keep what you think is in your best interest, i love the deck. Keep up the great work!!!

not bad, i would suggest running Voyaging Satyr instead of Sylvan Caryatid since you can untap your Nykthos, Shrine to Nyx . i also love Genesis Hydra since you can pull an extra creature out. lastly i may suggest finding a spot to put in some Karametra's Acolyte since it is a creature version of Nykthos, Shrine to Nyx

Update-Oct. 6, 2014

Deck still sucks.

All kidding aside Mono-Grn devotion already has some tried and proven lists and you don't seem to be trying to replicate or innovate on that in any beneficial way. You just put every big green hydra into a deck with Nylea and Bow and called it good.

Advocate that's not completely true he didn't use Heroes' Bane or Mistcutter Hydra . but otherwise i agree. If you want a deck like this that preforms a lot better, and is well constructed check out Ramp Like A Half-pipe