I don't generally build (mono)black decks, so I can't be too much help on deck specific advice, but I can provide some more general tips. That having been said, 40 land is generally too much if your deck doesn't do something specific with lands, you should be able to cut between 3 and 5 lands in my experience.
In addition, black has some great mana doublers. If they are within your budget, running magus of the coffers, crypt ghast and/or Nirkana revenant is something you should consider instead of those lands. Th same goes for some more mana rocks. Since your commander allows you to sub out B costs, you might want to consider something like a worn powerstone or hedron archive.
For your first deck, you just want to get it together and running then you can slowly work on upgrading it as you play the deck to work out what it needs to succeed.
I am a super organised and systemic person, so I like to build a deck this way. I had a thunderstorm knock out my internet last week so I went and build a deck recently haha
Just pick up all the black cards you have that might be good then start sorting them into piles.
The first pile is key to your deck, whatever your main win con and goal is, That pile should basically not be cut from your deck until the last tough cuts part of the process. Then gather all the Important role Players. Value and card draw, Ramp and Removal, straight-up good stuff. Then stack them on how good you think they are (you can be wrong that's okay)
Then take the top and middles of those piles to create new piles. Then dismiss the rest. So now you have Key to your deck, The cream of the crop and Pretty Good piles.
I keep the pretty good pile around because often you'll have critical removal and card draw and ramp and stuff that's not the best but you'll find you'll need it later to get your deck to run well.
Usually i tend to stay away from those cards as well, but for this deck they can ease up the life costs that come from playing K'rrik. Also, do you means bad as in unplayable or bad as in badly designed?
Currently using a precon for my games, and am looking to upgrade.
Cards in this deck that i own.
Twilight Prophet
Grey merchant of asphodel
sanguine bond
The Eldest Reborn
Nykthos, Shrine to Nyx
Sol Ring
Staff of the death mangus
Drag to the underworld
Rise of the dark realms
any tips?
In addition, black has some great mana doublers. If they are within your budget, running magus of the coffers, crypt ghast and/or Nirkana revenant is something you should consider instead of those lands. Th same goes for some more mana rocks. Since your commander allows you to sub out B costs, you might want to consider something like a worn powerstone or hedron archive.
Lastly, I'd run at least one of underworld connections or phyrexian arena. The Arena is the better card, but it's also a lot more expensive.
I am a super organised and systemic person, so I like to build a deck this way. I had a thunderstorm knock out my internet last week so I went and build a deck recently haha
Just pick up all the black cards you have that might be good then start sorting them into piles.
The first pile is key to your deck, whatever your main win con and goal is, That pile should basically not be cut from your deck until the last tough cuts part of the process. Then gather all the Important role Players. Value and card draw, Ramp and Removal, straight-up good stuff. Then stack them on how good you think they are (you can be wrong that's okay)
Then take the top and middles of those piles to create new piles. Then dismiss the rest. So now you have Key to your deck, The cream of the crop and Pretty Good piles.
I keep the pretty good pile around because often you'll have critical removal and card draw and ramp and stuff that's not the best but you'll find you'll need it later to get your deck to run well.
As for a specific card suggestions: Torment of Hailfire, Go For the throat and Murderous Cut are great black removal. There are a surprisingly high number of indestructible creatures so you need some exile removal such as Ashes to Ashes, Silence the believers and sever the bloodline. Do you have any wraths? Crux of Fate, Decree of Pain, Mutilate. I have a visceral hate for the life gain artifacts Demon's horn and Staff of the death magus they are quite possibly the worst cards in recent magic history.
Pioneer:UR Pheonix
Modern:U Mono U Tron
EDH
GB Glissa, the traitor: Army of Cans
UW Dragonlord Ojutai: Dragonlord NOjutai
UWGDerevi, Empyrial Tactician "you cannot fight the storm"
R Zirilan of the claw. The solution to every problem is dragons
UB Etrata, the Silencer Cloning assassination
Peasant cube: Cards I own
Pioneer:UR Pheonix
Modern:U Mono U Tron
EDH
GB Glissa, the traitor: Army of Cans
UW Dragonlord Ojutai: Dragonlord NOjutai
UWGDerevi, Empyrial Tactician "you cannot fight the storm"
R Zirilan of the claw. The solution to every problem is dragons
UB Etrata, the Silencer Cloning assassination
Peasant cube: Cards I own