The idea is to live the Mono Black Dream of paying a shit ton of life to win the game.

Pain Seer + Sign in Blood + Read the Bones + Erebos, God of the Dead give a ton of card draw.

Squelching Leeches gets big fast, and if I'm able to bestow a Herald of Torment ... things get crazy.

Gray Merchant of Asphodel gets back the life lost and deals a massive blow the the opponent.

Whip of Erebos gets back the life lost and gives Gray Merchant of Asphodel another hit.

Round out the rest of the deck with removal, and you have yourself Mono Black