I would suggest replacing Ruin Rat with Aether Poisoner. I don't see why you would need the exile effect, so even if you don't want to swing, it's just as good. It also opens up for using Glint-Sleeve Siphoner.

If you plan on making use of God-Pharoah's Gift, include 2-3 copies of Gate to the Afterlife. Otherwise you will end up with the gift in hand, before you get the gate half of your games, and im not sure you want that.

Your curve is very low, so the curse seems bad. If you plan on making a high tempo play by investing in a one-drop on t1, then you don't want to immediately fall behind again on turn 2/3. If you want to slowly drain, may I suggest a card like Torment of Scarabs. You will unlikely want to play Trespasser's Curse before turn 4 anyway, and by then they will only have to play around 4-6 creatures to beat you. Torment of Scarabs on the other hand, will likely trigger 3-5 times, which should grant you better value.

Also be aware that Walk the Plank does not hit merfolk, which will likely soon be very relavant.

As mono b aggro player, i can suggest u some tips : 4 copies of Gonti are too much, as legendary creature u wont see him much more than 2 copies for game.Also , Gonti is a sideboard answers to many decks.

Same for Yahenni, try 3 max copies with Last Reckoning into play for the combo.Dread wanderer is a super card, and u need that for the Ruin rat. Also Scrap-heap Scrounger is a must-have, u can put it for viciuos conquistador.

I dont'like the god's pharoh's gift, as u need a different deck to build for this kind of deck.Put Vraska Contempt and/or Never/Return for some copies of Walk the plank.You absolutely need x4 Fatal push for the Trespasser's Curse.

I have this exact deck well the mono black aggro. 3 heart of kiran and 2 aethersphere harvester are beats with the lookout as you crew and drain. 4 glint sleeves. 4 dread 3 gifted aetherborn 3 ruin raiders 4 scrap heap 2 yehenny and 2 bone picker. 4 push 2 walk the plank 2 super natural stamina. 12 swamp 4 aether hub 4 infir deadlands. Im 9-2 at fnm.Side 2 bontus2 gonti 3 duress2 harsh scrutiny 2 fourth street brawler2 vraska contempt2 key to city

Tylerdurden803 if you wanted to show off your decklist, you could have just posted a link. Seems like a solid deck though. Also, remember to press enter twice to go to a new line.

Just like that...