Unleash the Hydras

I would suggest a more focused approach. Take some of you consider the best hydras, instead of trying to have them all. Add some more mana ramp; bump up the Elvish Mystic to four add some Llanowar Elves, Golden Hind, or Sylvan Caryatid. Since you are running modern you could add some Elvish Piper to cheat in your hydras for cheap. So instead of trying to hold out you can come out swinging and bring the fight to them. I hope this helps. If you get a chance check out some of my decks, particularly this one:

http://www.mtgvault.com/bppride817/decks/hydra-devotion/

What cards should I get rid of then? Also if I use piper to cast a hydra would i need to pay mana to increase its power and toughness?

Get rid of:
2x Deus of Calamity
1x Dungrove Elder
3x Kalonian Tusker
1x Rampaging Baloths
2x Reverent Hunter
1x Thragtusk
1x Witchstalker
1x Rancor

Consider adding/losing:
Elvish Visionary (doesn't really give the card advantage that you need)
Fog ( if you are going to have them might as well run four)
Asceticism (at least two this card seems great)
Elvish mystic (like you said about the hydras with X in their mana cost but there are plenty of powerful hydras that d have X in their mana cost)
Planeswalker removal

Add:
1x Elvish Mystic
4x Llanowar Elves -or- Sylvan Caryatid
1x Karmetra's Acolyte
4x Scryb Ranger (to untap the acolyte for more ramp and chump block)
4x Arbor Colossus -or- Skylasher (to handle flyers)
Some kind of artifact and enchantment removal

I'm gonna clone the deck to my account and fine tune the build. We should connect on Facebook I have a handful of hydras that I picked up when building my deck that I could send out to you if you are using physical cards.

Good suggestions. But why get rid of kalonian tuskers? Theyre great for devotion.

Turn two you most likely would want to drop more mana ramp Elves, Hind, or Caryatid so on turn three and or four you start dropping your big Hydras at that point you really won't need the Tuskers. You don't have to get rid of anything you don't want to tho.

Here is the deck with the changes I made:

http://www.mtgvault.com/bppride817/decks/unleash-the-hydras/

And I was serious about getting you those cards if you play with physical cards. I have 1x Nessian Wilds Raveger, 1x Primordial Hydra, 4x Heroes' Bane, and 3x Vastwood Hydra that I'll never use and no one wants in trade. Look me up on Facebook same user name as on here and we can work it out.

Hey thanks for the offer but I'm fine. I replaced most of what you suggested with elves. Ill try to get my hands on some caryatid.

Im sorry, could you explain how this would work?

Sure, lets say you have a Nykthos in play, a devotion of eight and four forest.
Tap your Nykthos spending two to tap it giving you eight mana plus the other two.
Now, since you haven't played a land, play another Nykthos, leaving you with ten floating mana.
Legendary rule comes into play so you need to sacrifice one of them, the older one.
With ten mana floating spend two on your new Nykthos in play adding sixteen mana to your mana pool.
Then playing a huge Hydra for the following mana.

Ah! Thats clever. I'll definitely add that in there.