I would add Simic Manipulator and Bioshift .

Bioshift is too weak of a spell for my mid range to late game deck. Sure it might be good for my elusive krasis or to buff a single creature but the amount of decks with removal is very high, therefore having a more creatures moderately buffed would be better. As for Simic Manipulator, i feel that there is no room in my deck for another 3 drop, and my original 3 drops are already very strong. But I will put them in my maybe board because these 2 cards might find their way in as other decks change. Thanks for the ideas.

Polukranos sucks. I would remove it. Rest seems okay

AEtherling , Polukranos, World Eater and Arbor Colossus are fantastic cards but seem out of place here. Go for another Kalonian Hydra . you could drop the Prime Speaker Zegana for either another Prophet of Kruphix or Progenitor Mimic . A problem with this deck is that most of your creatures are either low or high in mana cost. You have 13 cards that are 4 or more to cast. Since Vorel of the Hull Clade and Master Biomancer are primarily used to block and stack counters, this leaves most of your offensive power is pretty much stacked on both ends of the mana curve. I'm also not a fan of running single copies of cards. Increased count = likelihood of drawing them is higher. The 1x Rapid Hybridization and Bow of Nylea irk me. If you don't want to lower your curve, take out the Experiment One and the Rapid Hybridization for a playset of Elvish Mystic for more mana.

I might take out Polukranos, World Eater for Kalonian Hydra ,which could help or hurt my mana curve. This deck as it is right now is doing very well. Ive been playing the popular decks such as white weenie, red deck wins, american midrange, izzet, green white, and blue black control, and coming on top of every one with the help of a smart decision on sideboards. The reason this deck does so well is because i can often pull my one drop first turn, followed by Sylvan Caryatid (sometimes not always) then into Vorel of the Hull Clade or Renegade Krasis granting 2 +1/+1 counters to my 1 drop. By turn 4 (or 3 w/caryatid) i drop Master Biomancer granting even more counters. Turn 5 i can play the large creatures, such as Kalonian Hydra or Prime Speaker Zegana who is great at reimbursing me with cards. I run only one Rapid Hybridization and 1 Bow of Nylea because these are very situational draws,but always come in handy with one in your hand, and drawing two in your hand or even drawing a second in one game can be detrimental to your creature ramp up. I have the toughest time playing super control decks, but sideboards such as Negate , Witchstalker and Savage Summoning prove too strong. Ratchet bomb for the aggro decks as well as cyclonic rift to stall. Plummet is for the mythic creatures and rare who are devastating when played. This is a general playstyle of this deck. Im trying to make simic become a top 16 contender guild. Thanks TheDevicer for the advice, and I might soon be putting in Kalonian Hydra

I've been running Beetleform Mage since day one, BUT with that said I switched him out finally, something to consider is Zephyr Charge if you replaced say, 2 mages for 2 charges, you would still be spending that 2 mana for flying, but it could be any one of your creatures, just a thought, check out my deck and tell me what you think, it still needs adjusting! http://tappedout.net/mtg-decks/my-simic-deck-early-stages/ Its actually going to see quite a bit of changes, I just traded for to mimics, I'm so stoked, keep us posted on how your deck goes.

Sideboard option by the way,Mistcutter Hydra , great against those pesky blue control decks

i'm going to agree with derecksisco, except that I would definitely mainboard Mistcutter Hydra , considering you already have Kalonian Hydra in there. They're practically best friends.

Just made alot of changes so let me know what you guys think

looks pretty competitive, the biggest weakness I see is you definitely have to play around the Supreme Verdict against a blue/white control deck. But the hydras should be awesome to play afterwards. You might just need a forth Simic Charm in your sideboard to deal with decks that have a lot of targeted removal like Doom Blade . Those are pretty popular where I play.

be careful of your mana curve, you have no 3-drops, Boon Satyr and Give / Take (i count this as a 3-drop, take isnt that great, give rocks) are solid 3 drops cards. you should also lower your count of 4=5 drop cards, as simic you lack any form of early game control the chance you will actually need 4 Prophet of Kruphix or Kalonian Hydra is extremely rare.

another thing, again simic lacks that early game control, and lacks the power gained from spare mana that gruul has, you have absolutely no need for Manaweft Sliver , and Elvish Mystic feels out of place, you would be better off solidifying your early game with something like Experiment One or Cloudfin Raptor and come turn 2 even if you got Elvish Mystic out on the battlefield, he does nothing, you have no 3-drop play for him to ramp into. if you really want more ramp than just Sylvan Caryatid (who is amazing in simic because it almost always triggers evolve on early game creatures) i would recommend maybe Gyre Sage who may-be slower, but can be quite potent with x-cost cards like Mistcutter Hydra . also Gyre Sage combos with Give / Take (give side) and Burst of Strength you can get mana from gyre much faster than a Manaweft Sliver or Elvish Mystic .

Master Biomancer is a must in any mid-range/combo simic deck, he is out of Lightning Strike range, and is extremely potent, and can be a turn 3 play with a Sylvan Caryatid . but the best part, is Kalonian Hydra as he gives counters, which hydra then doubles.

Scavenging Ooze is another great card, creatures are ging to die as the game progresses, its a given, so he will always have targets, which gives you a little healing, and makes him a menace, compunded with a Kalonian Hydra he is a nightmare.

Urban Evolution ive never seen a use for this card in aything but limited, it is overcosted for its effect, there are much better simic draw effects, and the extra land is unnecessary, Ordeal of Thassa is just broken with evolve, as you can usually get 2 counters on something like Cloudfin Raptor or Experiment One by turn 3-4 and then cast this, and swing, getting you a +1/+1 counter, and 2 cards for (1)(U), Fathom Mage and Zameck Guildmage also give some strong early card draw. you also have Prime Speaker Zegana giving you a lot of late game card draw, further lessening the need for an Urban Evolution .

guildgates slow you down, and provide no bonus, with 4 Breeding Pool , and 4 Temple of Mystery . you have enough color fixing.

and on a final note, you have no removal, this depends on your metagame, however, in my metagame, you need removal or you get stomped, as it is a lot of combo decks, late game stomping, at the very least i would put some Rapid Hybridization in the sideboard just in case.

Your deck isn't a bad deck, it just has a few issues which i have tried to help you out with, in my own long winded way.

Whoa lots of changes, well here's the scoop, I too made a TON of changes seeing that I really wanted to work around Simic Manipulator , my deck used to just be creatures creatures and ramp into creatures, which sadly competitively leaves you WIDE open, burn spells as well as your common Doomblade can just be a STRONG torn in your side, but this is what I thought. I'm running Master Biomancer and Vorel of the Hull Clade as well as Simic Manipulator and Gyre Sage these guys are all great and all have their place, just like your hydra's but what seems to be the biggest pain to deal with? If your deck runs anything like mine I bet a beefy creature isn't a threat to you, an enchantment that gives your opponents creatures lifelink... who cares, your dealing damage in bulk. What most likely ruins your day is spot removal

EX: you are about to make a big play, you have your Mistcutter Hydra on the field and your about to flash in Kalonian Hydra at your opponent's end step so you can pummel their face on your next turn, and WHAM they counter your hydra with Essence Scatter or kill it with Doom Blade or some other problem

I've found that my biggest issues are instants that clear my hard earned bulk of a creature from the field, it is for this reason that I suggest one of two very simple solution cards Dispel and Mizzium Skin I think this would replace Urban Evolution very nicely mainly because I feel that Urban Evolution boils down to mana ramp, as Baycer mentioned isn't really doing much for you, I personally think that the ramp isn't going to help you once you hit your 5 lands, you don't have anywhere to sink it, something like Ooze Flux and Master Biomancer creates a viable outlet for you to dump that mana, or even Zephyr Charge lets you do something with it, I think Zameck Guildmage would be an interesting card in your deck, just because your dealing with counters, it gives you a reliable way to draw cards, or even dump mana into making a late game Elvish Mystic come in with counters. But like I said Mizzium Skin or even Dispel would be a reliable way to ensure that your stuff stays on the board, they're very specific, but its inexpensive, just some food for thought, here's the way my deck used to look in case you wanted to see some of ideas My Simic deck (early stages) Predator's Rapport is also an easy way to recuperate from some of that early game damage . Keep up the work its looks fun

Spell/Removal decks are annoying, but if you are playing a removal deck just play slowly, and drop one big creature ever so often or wait to play Plasm Capture to play into Mistcutter Hydra or the other hydra. 3 drops are a bit of a pain to find for this deck, seeing that Boon Satyr dominates everything, and Give / Take is just lame for the "take" part of it. Im trying to fit in boon, but the only thing I can think of would be to drop the 2 AEtherling out and drop 2 Manaweft Sliver to pump in 4 Boon Satyr I really rely on mana ramping and taking out them hurts the reliability of this deck.
Aggro decks is at its prime in standard, seeing that almost all of the top decks are aggro, its difficult to get past turn 4. With the dependabilty of mana ramping, by turn three i can move into Kalonian Hydra , Prophet of Kruphix Mistcutter Hydra which makes the aggro decks scoop and sideboard in removal, seeing that there is no way they can take down an 8/8 trample (unless its boros with Chained to the Rocks but who cares about boros is broken atm with Spark Trooper ). Unfortunately I can not play this deck tonight at fnm because I cant find 2 more kalonian hydras from anywhere, nor 2 mistcutters, but I will play the most of it for fun and see how it goes. Thanks for your comments and keep commenting!!

For control decks i also have my sideboard of Swan Song and Savage Summoning . But lets be honest, the amount of control decks is being dwarfed by the amount of aggro decks out there.

I totally forgot about the x in mistcutter, mana dump there is worth it, ya know Faerie Impostor is actually playable with prophet of krupix, as a counter/emergency bail-out for something like supreme verdict or other removals. I'm really looking forward to see how the deck plays, I guess then you'll have a better idea of any changes you may want to make, or if it perfectly stomps face as is!

I've got a pretty similar standard Simic deck as well, and after two FNM's I've found that it absolutely sucks to play this guild against Esper and Grixis control decks. In order to help combat Esper, I had to add in 4 Pithing Needle for the planes walkers and Aetherling, and some dispells or enchantment destruction to stop the Detention Sphere's that will obviously be placed on them. Still haven't figured out how to stop Grixis control.

To sum up, might want to put some two more Naturalize and a play set of Pithing Needle into your side board.

Anyway, definitely getting a +1 from me, I love Simic decks. If you wouldn't mind checking my deck out and leaving some feedback and a +1 if you like it, i'd appreciate it. Here's the link The Name's Agent, Fate's Agent..