Sewer Nemesis isn't modern legal, but otherwise I like it a lot. +1

slaftergames, that is a very good point and I feel silly for missing that. I'm going to set this to casual for the time being until I can find a good modern-legal replacement.

Right now I'm looking at Crowd of Cinders, Umbra Stalker, Mortivore, or bringing back Marrow-Gnawer.

Marrow-Gnawer would be my pick of choice from that list, but that's just my two cents.

Depending on your meta, you might consider these cards with madness as well: Alms of the Vein, Asylum Visitor, Big Game Hunter (probably better in the side than in the main, but again that depends on your meta).

I'd definitely also put some unconditional or non-color-based removal in the sideboard, or I suspect the deck's going to struggle a bit against mono-black.

My only concern with Marrow-Gnawer is that he's legendary and it leaves me with really just Pack Rat as my threatening body. It is nice to drop him and rush down with an army of fear rats, though, so if we can go wide enough before hand it could be a game-winner. Plus its an enabler for Drainpipe Vermin, so there is that. How many would be appropriate, 2 or 3?

I like Big Game Hunter in the sideboard, for sure.

I had considered Alms of the Vein for a while, but I'm not sure how well it can fit as it doesn't impact the board, though I do like the life gain option, especially with Sign in Blood. I've had it in the maybeboard for a while, so I guess I should actually test it.

Asylum Visitor is an interesting take on bob that I was really excited for when it was revealed. For some reason I was under the impression she cost more, so thats definitely an option to come back to. A bigger butt would make me a lot happier, for sure.

That's a good point on colorless removal. Go for the Throat is my go-to colorless removal, so maybe running 4 in the sideboard to swap out Dark Withering if need be.

I would highly recommend trying out Smuggler's Copter. Smallpox can also be useful in a deck like this.

Cool deck. I'm trying to build something around Pack Rat right now too so I like your style. I'd suggest adding a couple Raven's Crime for their versatility. Target yourself for madness or your opponent when they're low on resources and use its retrace feature when you top deck a land when you don't need one. Plus you don't need to reveal your hand if you target yourself like with an Inquisition of Kozilek or Thoughtseize.

jgc10

Glad you like my ideas. Its actually funny that you would mention Raven's Crime since I was just looking at it recently as a replacement for Duress. My only issue with it is that you lose the ability to see their hand and choose what they have to throw away. I did some playtesting, though, and it was great early game fuel, so I'll definitely see how it performs.

Do you have any ideas on card draw? Right now I can go hellbent quickly and then my only way to sustain is between Asylum Visitor and Key to the City, which are situational and mana intensive.

I've been play testing some Altar's Reap for card advantage. I want something I can use at instant speed, so Read the Bones and Sign in Blood aren't options right now, but Shadow of Doubt is a sideboard play. There's also Blood Scrivener and cards like Underworld Connections and Phyrexian Arena if you want to go the enchantment route. I've also had good success late game with Ob Nixilis Reignited. If you have a creature or two to protect him, he's a beast. You have a lot of one drops, so maybe replace a couple of those with some bigger threats would help smooth your mana curve?

I like Shadow of Doubt in the sideboard, for sure. As far as the main deck goes, I'll need to try out ~2 Underworld Connections and see how they go. I could see them being perfect mid-late game; same for Ob Nixilis Reignited. I'm not sure I'm running enough creatures/token generation to make efficient use of Altar's Reap.

One thing that I've noticed is that with Asylum Visitor on the field, Rotting Rats, Stronghold Rats, and Raven's Crime have been consistently netting me draws on my opponents' upkeep, so the advantage potential is definitely there.

I'm currently trying these changes:

-4 Duress

-4 Aphotic Wisps

-1 Rogue's Passage

==========

+4 Raven's Crime

+3 Underworld Connections

+1 Swamp

+1 Dakmor Salvage

The Raven's Crime's have been working well, especially with Dakmor Salvage, but I'm not liking the Underworld Connections. They really want to be in a more control-oriented deck under perform. Ob Nixilis Reignited is fun and a good top for the curve, I'm just debating running 2 or 3 because I don't have any way to reliably fetch him later in the game.

For now I've swapped back to these changes for game night:

-3 Underworld Connections

===========

+1 Alms of the Vein

+2 Murderous Compulsion