Razorarrowz

Riddlekeeper is not modern legal :)

I really like the overall idea. I don't think this will ever become a tier1 deck, though.

That said, I think you should see what you can make of it! Here are some of my suggestions:

Obviously, you need to work on your mana base. With the next to limitless options to control your colors in freeform, you can do much better depending on your purse. I understand this is a budget deck, so I wont talk much about fetchlands, shocks etc, but the check lands like Dragonskull Summit really isn't very costly nowadays. Additionally, you can try cards like Ghost Quarters. Try mixing this with your Crucible of Worlds and let the festivities begin. Before you know it, your opponent is bled dry for basics and on his way to impending doom.

I fear you might find yourself very vulnurable to early threats like aggro creatures and/or the cheap counterspells avaiable in freeform magic (Counterspell, Remand, Mana leak etc). Maybe remove a few of your CMC3 land destruction spells and use some of the very powerful CMC1 discard spells like Inquisition of Kozilek and Thoughtseize. On a budget, take a look at Duress and Despise.

If you can find space for some of the good spot removals too, that would be nice. I'm thinking Lightning Bolt, Terminate, Doom Blade etc. Most of them are certain kills early game, and if your game plan behaves, your opponent shouldn't even get to their late game stages.

I'm, obviously, a very big fan of land destruction myself, and i'm trying to make it work in Modern. You can take a look at my current deck list if you will :) Please note it consist of the cards I actually own, and my planned changes can be found in the description below the list :)
http://www.mtgvault.com/razorarrowz/decks/razorpox/

Winther 37 humans, you ought to find space for 4 Cavern of Souls in your manabase

Razorarrowz
Grixis92

Hate to break it to ye, man.. But Griselbrand is kinda banned in EDH :P

May I be sold "bolt" as to ask where LightningBolt is? :)

You kind of forgot the bomb, mate xD

i'm afraid you have misunderstood the rules about which cards you can use for Commander.

You cannot use cards like Judge's familiar to a mono white deck, because a non-white mana symbol appears on either its casting cost or rule text.

The rule is as following:

A card may not have any color identity which your chosen commander doesn't. Color identity is determined by the colored mana symbols in a cards casting cost as well as its rule text.

I highly recommend Selesnye Charm.. All of its abilities are relevant.

With green at your disposal, adding a minor amount of Black mana shouldn't hurt you much, opening up for Lingering Souls.
Consider doomed traveler for sideboard against highly aggressive decks and you nede an early blocker.

Take a look at Goblin Assault - mostly against control decks that Will make the game last forever. Constant tokenspawn will cause them a great deal of stress.

Another great charm is Boros Charm. This too has alot relevant uses, f.eks. protecting your army from wrath effects

Consider using "Simic Growth Chamber".
Once one of them is on the battlefield, and you draw the next, you will have at least one landfall a turn :)

Birds of Paradise can add any color mana

I believe i would replace Centaur Healer with Kitchen Finks.. Cloudshift and Conjurer's Closet makes it almost impossible to kill.

Take a look at fiendhunter, and read some forum on its abilities when mixed with flicker.
I believe there is enough lifegain without the sanctifiers.. Try out Wall of Omens or Elvish Visionary instead

I like your idea, but I fear you might have misunderstood Abundant Growth.. The card does not ramp, it just gives your land the ability to tap for any color mana.

Triton tactics is a brilliant idea! And again i point out the use of Consuming aberation. The spell will make it even larger, making it mill even more. Seems pretty legit :)

Combined with Phenax??

Whatever became of Consuming Aberation??
[T]: Target player puts cards from the top of his or her library into his or her graveyard, equal to the amount of cards already there.

Do that twice and see your opponents face :) Plus the beast offers you an alternative win condition :)

I like the idea, but i disagree with the use of Whip of Erebos and Shadow Alley Denizen.

As for the whip, I hardly believe your creatures are big enough to make it worth a while. I would rather look into some of the great sac-outlets your colours have to offer.

Shadow Alley Denizen suggests the use of many black creatures. As it is right now, you barely have any. Additionally, your creatures do not have any size of special abilities, that makes the "unblockability" worth much.

I believe your idea with Curse of the Swine is awesome, but i also believe you can find more powerful and effective ways to abuse the temporary control of opposing creatures.

Overall a brilliant idea - the foundation is there, now you just need to build and improve. Try looking into your options at sacrificing creatures as a cost for some valuable ability :)

I would see if I could find space for 2-3 Mutilate for some additional board control.

Dark Confidant could also become very useful to you, looking at your decks mana costs. Vampire Nighthawk and Deathrite Shaman should be able to outheal most of the damage.

I totally love your deck!

For quite some time, I've been looking for something new to try, and I think this is it, or at least something similar.

I am afraid you can't save Obzedat from the whip. The whip says, it will exile the creature permanently, should it leave the battlefield. This, the whip will always win the stack against you - it's still a rather powerful combo, though

Have you considered using "Sanguine Bond"? Discarding a card to Trading post will also deal 4 damage to an opponent, then :)

I don't think a deck like this should actually use guildgates, but if your gaming experience tells you the additional colors are needed, why not use Temple of Abandon? You might argue if it's a good land for aggro, but you can't argue if it's better than a guildgate.

Personally, I never found Gruul Charm a worthy card. I think I would drop them, add 4 Magma jet and remove 2 shock. I know your deck i supposed to be fast, but what really kills an aggro deck is not being able to cast creatures. A little scrying will help you out here.