VintageFTW

Maybe Revoke Existence in the sideboard to handle Gods.

What do you think of Thundermaw Hellkite over Stormbreath Dragon? Thundermaw Hellkite clears the way and nukes all Lingering Souls tokens. Stormbreath Dragon does dodge Path to Exile and can't be blocked by Lingering Souls, but it is a little smaller. I personally prefer Thundermaw just for the extra oomph despite Path.

Why the Undiscovered Paradise?

I'm interested in seeing Kruphix, God of Horizons in Journey Into Nyx.

Great deck! I would recommend Underworld Connections over Read the Bones. I would also say put 2 Rogue's Passages in to help your Master of Cruelties.

Perhaps you missed the word "Budget" in the title. Maybe you only worry about competitive Magic, but there are casual decks which are fun to play which don't run 4x goyf and no fetch lands whose purpose is merely 'fun to play.'

Now, in the realms of budget, I think he'd want to play something like Rancor. Just keep in mind that if the gentleman is making a budget deck, it's not really a consideration to run goyfs and shocks. $75 is usually a budget Modern deck, so try not to suggest anything that would break that cap and don't hate on the fact that deck chooses not to do so.

Last Breath checks its target upon casting and upon resolution. If the target is illegal upon resolution, the whole spell is countered. Its controller won't gain life.

I would instead suggest Ethereal Armor. Even if you have no other enchantments on the board, +1/+1 and first strike is still decent at one mana. Holy Mantle is also decent, as it makes them unblockable but also can lock down massive creatures like Arbor Colossus and Polukranos.

Veteran's Armaments triggers with half your creatures. I'd say it's worth a slot over Leonin Scimitar.

Oloro would probably be better along the theme for this deck. You can also add Dimir Machinations, Perplex, and Drift of Phantasms to tutor Paradox Haze and Copy Enchantment. Oh, and Enlightened Tutor.

I would put in two Rootborn Defenses. It populates your 5/5 trample wurm, and it makes all your creatures safe from Novablast, meaning you can alpha strike pretty well.

I have never seen Xenagos +1 outside of draft . . . just saying, I play him as a token maker and lightning rod.

The planeswalker almost serves as an easily killed enchantment that makes a 2/2 haste creature every turn. That's not really that good for this deck.

Myr Landshaper, and Smash to Smithereens fits pretty well on an Isochron Scepter.

How did you modify the color bar up top at the deck name so that's it's only green?

Maybe Thirst for Knowledge or Thoughtcast?
Love the deck!

Ash Zealot over Shred Freak. 2/2 First strike, haste is so much better than 2/1 haste. Also, Blood Crypt over Rakdos Guildgate any day.

What do you think of Flagstones of Trokair as your Mistveil Plains tutor over Marsh Flats?

It might be beneficial to run only two Mirran Crusaders mainboard and put in two Spirit of the Labyrinth. If you can AEther vial that guy right into your opponent's Brainstorm, they don't draw any cards but still have to put two from their hand on top of their library! It shuts down Jace, the Mind Sculptor and Brainstorm, which sounds pretty good to me.

Cavalry Pegasus may be good. Without Mono-Blue Devotion ruling the roost anymore, there aren't a lot of fliers running around standard besides maybe Desecration Demon and Nightveil Specter out of Mono-Black Devotion. Cavalry Pegasus gives all of your creatures flying except for Brimaz and his tokens, Boros Reckoner, and Dryad Militant (and unless you're afraid of Diluvian Primordial, you can replace it with another one-drop)

Nameless One?