Having played this a bunch and pretty much never one, I'd like to take a good look at this deck and see what I can do to rework it. I find myself running into the following problems:

1) Can't mill creatures fast enough2) Never enough mana to flood with lower-power creatures to use as blockers whenever #1 happens

First order of business is to add more mana. I'm probably going to move the two Tread Upon cards to sideboard. I'd initially included those because of my meta; the person I regularly play with has a deck with multiple Nighthowlers which abuses this deck's own gimmick, so Tread Upon was put in as a means to possibly overcome that. Anyway, with those out of the way, I'll add in one more each of Forest and Island. That puts me at 20 mana, but combined with the controlled mill cards and some of the other tweaks I want to make, that might be enough.

I'm considering removing the two Cancels as I pretty much never end up using them. If I have the mana to save for them, that generally leaves me unable to do anything else. I might sideboard a couple of Negates or something similar.

I'm also debating the Invisible Stalker + Bonehoard combination. While the former is great when paired with the latter, it's generally not that useful otherwise except as cannon fodder. Bonehoard doesn't feed my graveyard (for Splinterfright, Kessig Cagebreakers, and the like) if I accidentally mill it, but the fact that it's an equipment that can be transferred if it's "host" dies makes it too invaluable.

Also going to swap out the Llanowar Elves for Viridian Emissarys; they're cannon fodder, but the guaranteed mana upon death from the latter will be more useful than the tap-for-mana from the former.

I'm wondering if I should make room for just a couple of Boneyard Wurm cards in the mainboard. Some more grave feeders might be helpful, and even though they lack the trample-y goodness of Splinterfrights, they're cheap to put out and can be useful early game when the graveyard's still shallow. Between the Splinterfrights, Invisible Stalker + Bonehoard, and the wolf tokens generated by Kessig Cagebreakers, I think I've got enough ways to bypass (or at the very least overwhelm) enemy defenses.

hi there, interesting deck some suggestions:move Reclamation Sage to side deck.

-4 Viridian Emissary , +4 Satyr Wayfinder for extra mill.

-4 Mulch , +4 Tracker's Instincts flashback is great in case you mill it.

-4 Bonehoard ,+4 Nighthowler same mana costs for the same thing only its a creture so it adds up the creature count on graveyard.

-2 Roar of Challenge why add this? its socrery so it can't be used to defend creatures on opponents turn, and it sucks if it gets milled.

-2 Rogue's Passage, you dont need evasion actually. Kessig Cagebreakers win you by overhelming opponent with tokens and Splinterfright has trample.

At least +1 Life from the Loam trust me its worth its money.

Finally,

-2 Invisible Stalker +2 Marang River Prowler its +1 mana but it can be used from the graveyard.

Check out my deck that is similar-ish. Can't block this

Gakros - Thank you for your feedback! I really appreciate the suggestions. Some of those are cards I simply haven't heard of and are a big help! A few comments:

Reclamation Sage - I keep these in mainboard because of my local meta; every time I play without any kind of removal, it always comes back to haunt me. This at least gives me a chance to deal with it.

Tracker's Instincts - Didn't know these existed. Thanks!

Satyr Wayfinder - I just found out about this card. For my purposes, it's an objectively better Mulch and I was already going to swap them out.

Bonehoard - Nighthowler is great and I'd like to include him if I had more black mana sources. The thing about Bonehoard is that it's transferable; if the creature it's attached to dies, I can always give it to something else. It's also less vulnerable to removal.

Rogue's Passage - I have this in as a potentially-alternate win-con by allowing some other creature with a powered-up Bonehoard to guarantee a successful hit.

Roar of Challenge - I agree with your assessment; I had this in there as a way to hopefully a guarantee a good hit, but it never seems to pan out in practice. Out they go!

Invisible Stalker/Marang River Prowler - Interesting... I like that the Invisible Stalker is hexproof, but the River Prowler's usability from the graveyard makes it much easier to use. I like it!

Life from the Loam - That's more than I like to pay for a single card, but you're right, that'd be a godsend here. I'll proxy it for a while and see what I think.

Strength from the Fallen

I like how this deck looks so far. I love building budget Modern too, and also have a graveyard/dredge deck I've been working on (it's not on tappedout yet). Here are some cards that I know of that might be worthwhile:

Locket of Yesterdays, Boneyard Wurm, Ghoultree, Tilling Treefolk, Increasing Confusion, Gurmag Drowner, Screeching Skaab, Sultai Skullkeeper

There are also the green Bloodrush creatures, but they may be too aggro. Here are a couple: Slaughterhorn, Wasteland Viper

I know splashing black would be tough and/or possibly expensive, but if you did it would add some really nice options. You already have 4x Satyr Wayfinder, and 4x Opulent Palace so you might be getting close already. Some options:

Stinkweed Imp, Dakmor Salvage (once milled, it can dredge back into your hand if you need a land. These could even help you accomplish a black splash since milling yourself would help find them), Sidisi, Brood Tyrant (needs three colors but has a powerful effect), Vengeful Pharaoh, Phantasmagorian, Extractor Demon (cheap Unearth cost and is on-plan), Pit Keeper, Murderous Cut

Good luck with it!

Glad to know i helped. :)

About Nighthowler i had the impression you had more black,sorry.Also i am currently testing Groundskeeper as an alternative to Life from the Loam but like i said its totally worth it.Last note i believe you need a little bit graveyard ressurection and that is black color territory.there are some interesting flashback cards that could help you with that.Like Creeping Renaissance.Call creatures. you get all creatures from gy to hand (including Kessig Cagebreakers) and at the end of your turn you discard everything else.But its at 7CMC which is way high for me.

Oh quick idea to think instead of Bonehoard is Increasing Savagery but again high CMC.

Hope these help also. and you win your locals

Forgot to add Eternal Witness pricey i know, but it gets your milled plainwalker to hand and that is tempting. :)

Also if you are looking for more stable milling deck Moldervine Cloak and Golgari Brownscale are both epic,low priced,low cmc cards that i have tried.

I did run a Marang River Prowler + Moldervine Cloak deck but i simply like the explosive damage of Nighthowler / Bonehoard more.

i am Brainstorming you, i know :D

Yeah, I'm debating splashing black just slightly. I've only played a couple of games with this deck since incorporating the latest update, but I'm guessing I'm going to start finding that I have a lot more creatures going into the graveyard than I actually need; I might swap out some of my millers (e.g. Dream Twist, as it's a bit redundant now that I have Tracker's Instincts which are also flashback-able) and to make room for things that can answer threats or otherwise deal with other potential shortcomings. I'll play around with it some and see what I can come up with. The suggested Dakmor Salvage would be the perfect black land source to incorporate, in addition to the existing Opulent Palaces.

I've playtested this deck a few times and I'm much happier with it now! Between Splinterfrights, Kessig Cagebreakers, the Bonehoard + Marang River Prowler combo, and Rogue's Passage, I've got enough ways to bypass enemy blockers and hit for big damage. Stinkweed Imp can block and instant-kill fliers or heavy creatures and then be dredged back up for mill. I think I've eliminated all the redundant/potential dead weight in this deck and barring splurging for a single Life from the Loam, I don't think this deck needs any more work. Thanks for the feedback!