Oh Gary, how you make my day. As a mono black player: do not let them accumulate devotion. If you're aggro: kill stuff, swing. Do not let them keep Pack Rats, because strategy number one is: if rat, make more rat. I wouldn't worry so much about Erebos--he's good against control, but not as much against aggro (Stormbreath flies over him, Polukranos can stomp past him with a Ghor-Clan backing him up, etc) and is usually never sided in/sided out in that matchup. If you are playing control: DO NOT LET UNDERWORLD CONNECTIONS RESOLVE. They will win, and you will be sadsauce. Underworld usually comes out against aggro matchups and Erebos comes in against control. Mono-black is just an extremely flexible deck in general, so just keep that in mind when going against them.
if_then_else said:
On another note, do you have any suggestions to build a more or less good Golgari deck? I've been trying to build one, mostly using Lotleth Troll, Reaper of the Wilds, Scavenging Ooze and a lot of removal, but I can't make it work. I've tested with different spells and creatures, Courser of Kruphix, Thoutseize, more removal, etc... But I lose more often than not.
For early creatures is better Elvish Mystic or Experiment One for example? Garruk to synergise with the Troll or Vraska (or none)? What are good 3-drop for that kind of deck? Maybe some kind of "disrupt" deck with a lot of discard (although we don't have Innistrad's Liliana in Standard anymore...)?
I don't want a tournament winning deck, but something that is usable at a FNM.
It kinda depends on where you'd like to go (small, fast dudes or big, stompy dudes). Experiment One is awesome if you're trying to kill them as fast as possible. If that's what sounds good, I'd go with something like:
4 Experiment One
4 Rakdos Cackler
4 Tormented Hero/Dryad Militant (this slot is probably optional, 12 is a lot of one drops)
4 Lotleth Troll
4 Pain Seer
2-4 Varolz, the Scar-Stripped
Maybe Pack Rats? Possibly hard with trolls to feed
Removal/Discard (here's a pretty good spot for Deathrite Shaman + Drown in Filth)
Some number of Read the Bones/Underworld Connections
Nighthowler if you're me and you're running a ton of removal...
Land goes here
I wouldn't run Reaper or Garruk, unless you know you can take the hits from Pain Seer or aren't going to run him. Using Troll/Varolz as a place for all of your late-game 1-drops is really nice, though. But, you could always go with Angry, Stompy Golgari...:
4 Elvish Mystic
3-4 Sylvan Caryatid
4 Dreg Mangler
4 Lifebane Zombie (if everything is GR/Esper, this guy is a house of pain and suffering)
4 Reaper of the Wilds
4 Polukranos
4 Desecration Demon
Hand disruption/removal
Land goes here (I'd run a lot of Temples if you don't see yourself drowning in 1-drops)
You could easily splash red in this deck for Domri Rade and change Lifebane Zombie to Courser of Kuphrix for a ton of value. Unless you can get some solid green devotion going, I'd avoid Lotleth here, since it's just going to eat your hand and not be cool enough to get away with it. Reaper is awesome against people who don't counter it, but I'd make sure you've got enough mana to hexproof it if there's a good chance of it getting murdered.
Other 3-drops to consider: Herald of Torment, Boon Satyr (good if you're about to eat a Blood Baron)
Other good splash colors: White for his Blood Baronyness, Obzedat, Selesnya Charm or Red for Stormbreath, Domri, Xenagos (the god).
Sorry for the wall of text xD.