En!gM@

-4 Blight Mamba
-2 Ichorclaw Myr
-2 Revenge of the Hunted
-3 Rancor
-3 Wild Defiance
-3 Invigorate
-1 Distortion Strike
-6 Forest
-8 Island

+4 Noble Hierarch
+2 Become Immense
+3 Blossoming Defence
+2 Vines of Vastwood
+1 Dismember
+1 Mutagenic Growth
+1 Might of Old Krosa
+1 Groundswell
+2 Pendelhaven
+4 Inkmoth Nexus
+2 Breeding Pool
+1 Verdant Catacomb
+4 Wooded Foothills
+4 Windswept Heath

Having 8 fetch lands makes Groundswell more consistent and if you want the Turn 2 kill you described above, you need to play 4 Groundswell to have a higher chance of having 2 in your opening hand. Inkmoth Nexus is a great infect damage dealer that is a little harder to kill because it's a land on your opponent's turn. Passive pumps like Noble Hierarch and tapping for Pendelhaven can give you that 1 or 2 extra poison you need to kill your opponent so they should be auto-includes. It's also a plus that Hierarch is a mana dork for U & G. Blossoming Defense & Vines of Vastwood are great pumps that also offer protection from disruption. Invigorate is a great card but unless you're playing Vintage or Legacy, it's not legal. Revenge of the Hunted is a cool card but it kind of works against your strategy because it forces a block when you don't want your opponent to block. Rancor and Wild Defiance are both slow and Rancor doesn't pump or protect your creature enough to be worth the 1 mana cost. Remember, you're more than likely going to be operating on a 1-3 land mana base before you go for the kill. Any cards that cost too much for their worth slows your strategy down a lot. 8 fetchlands and 3 shocklands helps correct your mana base. You don't want to end up on an opening hand with 3 Islands and all green spells forcing you to mulligan. Hope that helps a bit.

-4 Bloodwater Entity
-4 Delver of Secrets
-4 Thermo-Alchemist
-4 Titan's Strength
-1 Dive Down
-3 Brute Force
-1 Slip Through Space
-1 Fling
-4 Sulfur Falls
-4 Mountains

+3 Enigma Drake
+3 Thing in the Ice
+2 Opt
+2 Serum Visions
+4 Mutagenic Growth
+4 Temur Battle Rage
+2 Manamorphose
+2 Steam Vents
+4 Scalding Tarn
+4 Flooded Strand

You need more lands so that you can actually play Turn 1 without having to mulligan a lot. Playing 8 fetches will help you mana correct so that you don't end up with red mana when you need blue and vice versa. It's also better to have redundancy with Enigma Drake as a baby Kiln Fiend rather than recursion with Bloodwater Entity since your goal is to end the game quickly. Delver doesn't really do anything after it flips except be an okay clock. Thing in the Ice is much more threatening when it flips, being a 3-turn clock and a board wipe, and doesn't just die to Lightning Bolt You don't need 8 pump spells because Kiln Fiend already pumps itself a lot when you cast essentially 0 cmc spells like Manamorphose & Mutagenic Growth. You'll find that digging deeper and always making sure you have cards in hand is much more important as disruption to your strategy is very real in Modern. Temur Battle Rage acts essentially as 4 more copies of Fling without the downside of losing your creature. Hope this helps.

Edit: Didn't see the budget tag. Rather than 4 Scalding Tarn, you can get 4 Polluted Delta. It's just important to have 8 blue fetch-lands so that you can cantrip Turn 1. If you really need red mana, use either fetch to get a Steam Vents.

Hopefully a reprint in M14? haha

Thanks for the advice

Yeah I was looking for potential ramps but the best ones are going to get cycled out soon so I guess I'll just have to wait until the next set comes out in hopes for better mana outlets.

This is a Standard build :P

Thanks for the input. The only reason I included Cluestones was because I felt like I needed to ramp more. It's a work in progress.

I'm playing Boros Aggro..

Updated OP:
+4 Ash Zealot
+1 Frontline Medic
+1 Searing Spear
+2 Legion's Initiative

-2 Plains
-1 Boros Charm
-3 Daring Skyjek
-2 Aurelia's Fury

Yeah I know those would be better options, but right now I'm not trying to spend too much money on this deck. I was thinking of putting in 2 Initiative for more protection and to help against Terminus sweeps. I still need to work on it but thanks for the input.

En!gM@